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  • 1. BAHAGIAN PENGURUSAN SEKOLAH BERASRAMA PENUH DAN SEKOLAH KECEMERLANGAN MODUL PERFECT SCORE SEKOLAH BERASRAMA PENUH TAHUN 2011 CHEMISTRY PANEL PENYEDIA DAN PEMURNI: Pn. Wan Noor Afifah Binti Wan Yusoff (Ketua) SBPI GOMBAK Pn. Aishah Peong Binti Abdullah SBPI TEMERLOH Pn. Norini Binti Jaafar SEKOLAH SULTAN ALAM SHAH Pn. Noraini Binti Zakaria SMS SULTAN MOHAMAD JIWA Pn. Rossita Binti Radzak En Che Malik Bin Mamat SMS TUANKU MUNAWIR SBPI BATU RAKIT En Jong Kak Ying SMS KUCHING En Ooi Yoong Seang SMS MUAR Pn Sa’adah Binti Mohayuddin SMS SERI PUTERI Pn Faridah Bt Hamat SMS TUANKU MUNAWWIR Chemistry Perfect Score Module 2011 1
  • 2. CHEMISTRY PERFECT SCORE MODULE 2011 CONTENT Guidelines & Anwering Techniques       Format of an instrument of chemistry Construct requirement Guidelines for answering paper 1 Guidelines for answering paper 2 Guidelines for answering paper 3 The common command words in paper 2 2 Set 1     The structure of Atom Chemical Formulae and equations Periodic Table of Elements Chemical Bonds 3 Set 2   Electrochemistry Oxidation and Reduction 4 Set 3     Acids and Bases Salts Rate of reaction Thermochemistry 5 Set 4    Carbon compounds Manufactured Substance in Industry Chemicals for Consumers 6 Set 5    Paper 3 set 1 Paper 3 set 2 Paper 3 set 3 1 Chemistry Perfect Score Module 2011 2
  • 3. CHEMISTRY PERFECT SCORE MODULE GUIDELINES & ANSWERING TECHNIQUES CHEMISTRY SPM Chemistry Perfect Score Module 2011 3
  • 4. GUIDELINES AND ANSWERING TECHNIQUES FOR SPM CHEMISTRY PAPER 1.0 FORMAT OF AN INSTRUMENT OF CHEMISTRY BEGINNING SPM 2003 No Type of instrument Type of item Paper 1 (4541/1) Objective test Objective it Number of question 1 Item 50 (answers all) Duration of time 1 hour 15 minutes 2 3 5 2.0 Paper 2 (4541/2) Subjective test Section A : Structured Item Section B : Essay restricted response Item Section C : Essay extended response Item Section A : 6 (answer all) Section B : 2 (choose one) Section C : 2 (choose one) 2 hour 30 minutes Paper 3 (4541/3) Written Practical Test Subjective Item : Structured Item Extended Response Item: (Planning an experiment) Structured Item : 1/2 items (answer all) Extended Response Item : 1 item 1 hour 30 minutes CONSTRUCT REQUIREMENT Construct Knowledge Understanding Application Analysis Synthesizing Science process Total mark Paper 1 20 m ( No 1- 20) 15 m ( No 21 – 35) 15 m ( No 36 – 50) 50 Paper 2 14 21 29 21 15 100 Paper 3 50 50 3.0 TIPS TO SCORE “ A “ CHEMISTRY 3.1 3.2 Familiarize with different types of questions as listed below and complete the previous SPM papers: 1. Objectives questions (MCQ) (Paper 1) 2. Structured questions ( Paper 2 & 3) 3. Essays (Paper 2) 4. Planning an experiment ( Paper 3) 5. Draw and label the diagram 6. Writing chemical equation( balanced equation, ionic equation, half equation) 3.3 4.0 Master the topics that contains the basic concepts of chemistry : 1. The structure of the atom 2. Chemical Formulae And Equations 3. Periodic Table 4. Chemical Bond Try to get : 40 marks above for paper 1  60 marks above for paper 2  40 marks above for paper 3 (Total = 180/2 =80 , A+ in SPM) GUIDELINE FOR ANSWERING PAPER 1 4.1 Paper 1 questions test students on 1. Knowledge ( Number 1 – 20) 2. Understanding ( Number 21 – 35) 3. Application ( Number 36 – 50 ) 4.2 Score in paper 1 Indicates student’s level of understanding in chemistry: Less than 20 – very weak 20 – 25 - weak 26 – 30 - average 31 – 39 - good 40 – 45 - very good 46 – 50 - excellent. 4.3 Answer all SPM objective questions (2003 – 2010). Objective questions for each year contain all topics. If your score in paper 1 is 40 and above, you will able to answer questions in paper 2 & 3 easily. Chemistry Perfect Score Module 2011 4
  • 5. 5.0 GUIDELINE FOR ANSWERING PAPER 2 (STRUCTURE AND ESSAY) 5.1 Paper 2 questions test student on 1. Knowledge 2. understanding 3. analyzing 4. synthesizing 5.2 Steps taken are: 1. Underline the command word and marks allocated for each question. 2. Match the command word to the mark allocated for each question. 1 point is awarded 1 mark. 3. Follow the needs of the question (Refer to the command words, page …….) 4. Unnecessary repetition of the statement in the question is not required. 5.3 Three types of questions which involve experiments in paper 2: I. Type 1 Describe an experiment on…………………Include a labeled diagram in your answer 1. Diagram 2. Procedure 3. Observation/example/data/calculation/equation/sketch of graph/conclusion II. Type 2 Describe an experiment……………( The diagram will support your answer.) 1. No mark is allocated for a diagram 2. Procedures 3. Observation/example/calculation/equation/sketch of graph/conclusion III. Type 3 Describe a chemical/confirmatory test for ……. 1. Procedure 2. Observation 3. Conclusion 6.0 GUIDELINE FOR ANSWERING PAPER 3 6.1 Structure Question 1/2 test the mastery of 11 Scientific Skills 1. Observing 2. Classifying 3. Inferring 4. Measuring (burette , stopwatch, thermometer, voltmeter) 5. Predicting 6. Communicating( e.g construct table and draw graph) 7. Space-Time Relationship 8. Interpreting Data 9. Defining Operationally 10. Controlling Variables 11. Hypothesizing Each answer is allocated mark as follows: 3 marks/2 marks/1 mark/0 Score : 11 X 3 = 33 Example of operational definition: 1. what you do 2. what you observe correctly Example: 1. When acid is added into latex, white solid is formed. When acid is added into latex, latex coagulated.- wrong 2. When the higher the concentration sodium thiosulphate solution is added into sulphuric acid, time taken for `X~ mark to disappear from sight is shorter. 3. When iron nail is coiled with copper and immersed into jelly mixed with potassium hexacyanoferrate(III) and phenolphthalein solution, blue spot/colouration is formed. Operational definition for 1. Rusting of iron 2. Coagulation of latex 3. Reactivity of Group 1 elements 4. Precipitation of silver chloride 5. Voltaic cell 6. An acid What you do When an iron nail coiled with a less electropositive metal is immersed in hot agar-agar added with potassium hexacyanoferrate (III) solution, When acid is added to latex When a metal which is lower in Group 1 is put in a basin half filled with water When silver nitrate solution is added to sodium chloride solution When two different metals are dipped into an electrolyte When a blue litmus paper is dipped into a substance which is dissolved in water, Chemistry Perfect Score Module 2011 What is observed Blue spots are formed White solid is formed Brighter flame is formed White solid is formed The needle of the voltmeter deflects Blue litmus paper turns red 5
  • 6. Hypothesis: Relate manipulated variable followed by responding variable with direction. Example: 1. The higher temperature of the reactant the higher the rate of reaction – 3 marks The temperature of the reactant affect the rate of reaction – 2 marks 2. Hexene decolourised brown bromine water but hexane does not decolourised brown bromine water. 3. When acid is added into latex, latex coagulates, when ammonia is added into latex, latex cannot coagulates 6.2 Question 3 (essay) Test The Mastery of Planning Experiment . Planning should include the following aspects: 1. Aim of the experiment/Statement of the problem 2. All the variables 3. Statement of the hypothesis 4. List of substances/material and apparatus – should be separated 5. Procedure of the experiment 6. Tabulation of data Score : (5 X 3) + 2 = 17 The question normally starts with certain situation related to daily life. Problem statement/ aim of the experiment / hypothesis and variable can be concluded from the situation given. State all the variables Manipulated variable : Responding variable : Constant variable: list down all the fixed variables to ensure the outcome of the responding variable is related only to the manipulated variables. Separate the substances and apparatus Separate the substances and apparatus Apparatus : list down the apparatus for the experiment. Example: Rate of reaction – stop watch Termochemistry - thermometer Procedure : All the steps taken in the procedure must include the apparatus used, quantity and type of substance (powder, solution, lumps … etc). No mark is allocated for the diagram. The complete labeled diagram can help students in : I. Writing the steps taken in the procedure II. Listing the apparatus and materials Tabulation of data:    The number of columns and rows in the table is related to the manipulated and responding variables Units must be written for all the titles in each row and column of the table DO NOT WRITE the observation/inference/conclusion in the table. Chemistry Perfect Score Module 2011 6
  • 7. 7.0 THE COMMON COMMAND WORDS IN PAPER 2 & PAPER 3 CHEMISTRY    The question normally starts with a command word. Students must know the meaning of the command word to make sure that the answer given is according to the question’s requirement. Match the command word to the mark allocated for each question. Command word Name/State the name (paper 2 & 3) State (paper 2 & 3) State the observation (Paper 2 & 3) Explain (Paper 2 & 3) What is meant by.. (Definition) (Paper 2 & 3) Describe chemical test (Paper 2 & 3) Describe gas test. (Paper 2 & 3) Explanation/example Give the name , not the formula. Example: Name the main element added to copper to form bronze. Wrong answer : Sn. Correct answer : Tin Give brief answer only. Explanation is not required. Example : State one substance which can conduct electricity in solid state. Answer : Copper Write what is observed physically. Example 1 : State one observation when magnesium powder is added to hydrochloric acid. [ 1 mark] Wrong answer : Hydrogen gas is released. Correct answer : Gas bubbles are released Indicate the change of colour , give the initial and final colour of the substance/chemical. Example 2: What is the colour change of copper(II) suphate solution. [2 marks] Wrong answer: The solution becomes colourless Correct answer : The blue colour of the solution becomes colourless Give the answer with reasons to explain certain statement / fact / observation/ principal. Example 1 : Explain why bronze is harder than pure copper [4 marks] Correct answer : Copper atoms in pure copper are all of the same size and ...........1 they are arranged in layers that can slide easily when force is applied ...........1 The presence of tin atoms in bronze that are different in size disturb the orderly arrangement of atoms in bronze. ...........1 This reduces the layer of atoms from sliding. ...........1 Give the exact meaning Example: What is meant by hydrocarbon. Wrong answer: A compound that contains carbon and hydrogen Correct answer: A compound that contains carbon hydrogen only State the method to conduct the test , observation and conclusion. Example : Describe how to identify the ion present in the solution . 3 Answer : - Pour in 2 cm of the solution in a test tube. Add a few drops of sodium hydroxide solution and the test tube is shake the test tube - A reddish brown precipitate formed. 3+ - Fe ions present State the method to conduct the test observation and conclusion. Example: Describe the confirmatory test for gas released at the anode (oxygen). Wrong answer: Test with a glowing wooden splinter. Correct answer: - Place a glowing wooden splinter to the mouth of the test tube - The glowing wooden splinter is lighted up - Oxygen gas is released - Describe an experiment ( 8 - 10 marks) (Paper 2) - Plan an experiment ( 17 marks) ( Paper 3) [3 marks] ...........1 ...........1 ………1 [ 3 marks] ..…….1 ...……1 ..…….1 No mark is awarded for the diagram. The diagram can help students write the steps taken in the procedure. List of materials 1m Can be obtained from the diagram List of apparatus 1m Procedure - ( 5 – 8 m) Observation/tabulation of data/ calculation/sketch of the graph/ chemical equation /ionic equation /conclusion …… etc. Any additional details relevant derived from the question. Answer the question according the requirement :  Problem statement/Aim of experiment  Hyphotesis  Variables  List of substances and apparatus  Procedure  Tabulation of data Note: For question 3, unlike PEKA report students only need to answer according to what is stated in the question. - No mark for the diagram. Diagram can help student writing the steps taken in the procedure. Chemistry Perfect Score Module 2011 7
  • 8. Describe the process … Describe the structure …. Describe and write equation… Describe how … (Paper 2 & 3) Predict (Paper 2 & 3) Compare (Paper 2) Differentiate (Paper 2) Draw a labeled diagram of the apparatus (Paper 2) Draw a diagram to show the bonding formed in the compound (Paper 2) Draw graph (Paper 3) Draw the energy level diagram ( Paper 2) Draw the arrangement of particles in solid, liquid and gas. (Paper 2) Draw the direction of electron flow (Paper 2 /3) Write chemical equation (Paper 2 & 3) Calculate (Paper 2 & 3) Classify (Paper 3) Give relevant details derived from the question. Make a prediction for something that might happen based on facts Example: Experiment 1 is repeated using a larger beaker. Predict the increase in temperature Answer : The increase in temperature is lower than experiment 1. Give the similarities and differences between two items/ situations Give differences between two items/situations Example : State three differences between ionic and covalent compound. Answer : State three properties of ionic compound and three properties covalent compound Draw a complete set up of apparatus (i) Functional set up of apparatus (ii) Complete label (iii) Shade solid, liquid and gas correctly. (iv) Draw an arrow and label ’ heat’ if the experiment involves heating (i)Ionic compound – The number of electrons in each shell is correct, 2 electrons in the first shell and 8 electrons in the second and third shell. – Show the charge of each particle. – Write the symbol of each element at the centre of the ion. (ii) Covalent compound  The number of electrons in each shell is correct, 2 electrons in the first shell and 8 electrons in the second and third shell.  The number of atoms sharing pair of electrons is correct.  Write the symbol of each element at the center of each atom in the molecule. Draw graph as follows :  Label the two axis with the correct unit  Choose suitable scale, the size of the graph should be at least ¾ of the size of the graph paper.  Plot all the points correctly  Smooth graph ( curve or straight line )  For the determination of the rate of reaction (i) Draw a tangent at the curve. (ii) Draw a triangle at the tangent Calculate the gradient of the tangent  Draw an arrow for the vertical axis only and label with energy.  Draw two horizontal lines for the reactants and products    Solid: Draw at least three layers of particles closely packed in orderly manner and they are not overlap. Liquid : The particles packed closely but not in orderly manner Gas : The particles are very far apart from each other Draw the direction for the flow of electrons on the circuit, not through the solution.      Write the balanced chemical equation Differentiate : (i) Balanced chemical equation (ii) Ionic equation (iii) Half equation for oxidation (iv) Half equation for reduction Show all the steps taken Give final answer with unit. Draw table to represent the classification. Chemistry Perfect Score Module 2011 8
  • 9. CHEMISTRY PERFECT SCORE MODULE SET  1. The Structure of Atom 2. Chemical Formulae and Equations 3. Periodic Table of Elements 4. Chemical Bonds Chemistry Perfect Score Module 2011 9
  • 10. PAPER 2 : SECTION A [STRUCTURE] 1 Diagram 1 shows the apparatus set-up used in an experiment to determine the empirical formula of an oxide of copper. Copper oxide Burning of excess hydrogen Dry hydrogen gas Heat DIAGRAM 1 The following data was obtained: Mass of combustion tube + porcelain dish Mass of combustion tube + porcelain dish + copper(II) oxide = 53.30 g Mass of combustion tube + porcelain dish + copper (a) = 25.30 g = 47.70 g What is meant by empirical formula? .............................................................................................................................................................. ……………………………………………………………………………………………………….. [1 mark] (b) Write a chemical equation for the reaction used to produce hydrogen gas. ……...................................................................................................................................................... [2 marks] (c) How to ensure that all the copper oxide is completely reacted? ……………………………………………………………………………………………………...... ………...……………………………………………………………………………………….......... [1 mark] (d) Based on the data given, determine the empirical formula of the copper oxide. [4 marks] (e) Write the chemical equation for the reaction between hydrogen and the oxide of copper. …………….......................................................................................................................................... [2 marks] (f) After the reaction is completed, hydrogen gas is allowed to flow continuously until the copper is cooled to room temperature. Explain why . ………….…………………………………………………………………………………………..... ………….…………………………………………………………………………………………..... [1 marks] Chemistry Perfect Score Module 2011 10
  • 11. (g) The empirical formula for magnesium oxide can be determined by direct heating of magnesium. Draw a labeled diagram to show apparatus set-up to carry out this experiment. [ 2 marks] 2 (a) 70.2 g of aluminium carbonate decomposed easily when heated to produce aluminium oxide based on the following equation. ................(s) → Al2O3(s) + CO2(g) [Relative atomic mass: Al: 27 ; C: 12; O: 16; 1 mole of gas occupied 24 dm3 at room condition] (i) Write the formula of Aluminium carbonate. …………..…………………………………………………………………………………... [1 mark] (ii) Write a balanced chemical equation for the reaction above. …………………………………………………………………............................................ [2 marks] (iii) Calculate the mass of aluminium oxide that is produced. [3 marks] (iv) Calculate the volume of carbon dioxide gas produced at room conditions . [3 marks] Chemistry Perfect Score Module 2011 11
  • 12. (b) Table 2 shows an experiment to investigate the effect of heat on metal carbonate. Diagram Procedure Metal carbonate is heated and the gas produced is passed through lime water. Metal carbonate Heat Observation White solid turns yellow when hot and white when cool. The lime water turns cloudy. Lime water Table 2 Based on the experiment: (i) Name the metal carbonate used. ………..................................................................................................................................... [1 mark] (ii) State the name of the products formed. ……….……………………………………………………………………………………... [1 mark] (iii) Write a chemical equation for the reaction. 3 …….…………………………………………………………………………….................. [2 marks] Table 3 shows the proton number and the number of neutrons for atoms P, Q, R and S. Atom Proton number Number of neutrons P 3 4 Q 16 17 R 16 16 S 19 20 Table 3 (a) (i) (ii) What is meant by the proton number? …………………………………………………………………………………………..... [1 mark] What is the nucleon number of atom P? …………….…………………………………………………………………………….............. A (b) Write the symbol for atom Q in the form Z [1 mark] X ..………….……………………………………………………………………………………… [1 mark] (c) Which atoms have the same number of valence electrons? …………………………………………………………………………………………………… [1 mark] Chemistry Perfect Score Module 2011 12
  • 13. (d) (i) Which atoms are isotopes? …………………………………………………………………………….................................. [1 mark] (ii) State a reason for your answer in (d) (i). …………………………………………………………………………….................................. [1 mark] (e) Diagram 3 shows a graph of temperature against time of substance X when it is heated until it boils. Temperature /oC F D 777 63 B E t3 t4 C A Time /s t1 t2 Diagram 3 (i) (ii) What is the melting point of substance X? ……….……………………………………………………………………………… [1 mark] Complete the table below by stating the physical state of substance X at the section AB and DE. Section Physical state AB DE [1 mark] (iii) Explain why the temperature remains constant from t1 to t2. ……………………………………………………………………………………… ………………………………………………………………………………………… [2 marks] Chemistry Perfect Score Module 2011 13
  • 14. 4 Table 4 shows the proton number of a few elements in Period 3. Element Proton number Sodium Magnesium Aluminium Chlorine Argon 11 12 13 17 18 Table 4 Based on Table 4, answer the following questions: (a) State two elements which are metals. ………………………………………………………………………………………………… [1 mark] (b) Chlorine is in Group 17 in the Periodic Table of Elements. What is another name for group 17? (c) …………….…………………………………………………………………………………… [1 mark] Write the electron arrangement of aluminium atom. (d) ……………………………………………………………………………………………………….. [1 mark] (i) Arrange the element in Table 4 according to descending order of atomic sizes . ……………………………………………………………………………………. [1 mark] (ii) Explain your answer in (d) (i). ……………………………………………………………………………………… ……………………………………………………………………………………… [2 marks] (e) When sodium is burnt in chlorine gas, sodium chloride is formed. (i) State one observation for the reaction. ………………………………………………………………………………………… [1 mark] (ii) Write the chemical equation for the reaction. ………………………………………………………………………………………… [2 marks] (iii) State one physical property of sodium chloride. ………………………………………………………………………………………… [1 mark] Chemistry Perfect Score Module 2011 14
  • 15. 5 Diagram 5 shows the symbols of atom of elements U, V, W and X. 7 3 U 12 6 V 19 9 W 20 10 X Diagram 5 (a) (i) Which element is an inert gas? ..................................................................................................................................................... [1 mark] (ii) Give a reason for your answer in (a) (i). ..................................................................................................................................................... [1 mark] (b) Element W exists as diatomic molecule. State the type of chemical bond in molecule W. (c) ........................................................................................................................................................... [1 mark] Element V can react with element W to form a compound. (i) Write the chemical formula for the compound formed. (ii) .............................................................................................................................................. [1 mark] Draw the electron arrangement for the compound formed. [2 marks] (iii) State one physical property for the compound formed. ..................................................................................................................................................... [1 mark] (d) Element U reacts with element W to form a compound . (i) State the type of the compound produced. ..................................................................................................................................................... [1 mark] (ii) Explain briefly how the compound is formed. ..................................................................................................................................................... ..................................................................................................................................................... ..................................................................................................................................................... [3 marks] (iii) Draw the electron arrangement for the compound formed. [2 marks] Chemistry Perfect Score Module 2011 15
  • 16. PAPER 2: SECTION B [ESSAY] 6 (a) Diagram 6.1 shows the electron arrangement for atom of an element from Group 17 in the Periodic Table of Element. Diagram 6.1 Based on Diagram 6.1, (i) Write the electron arrangement for the atom and state the name of the element. [2 marks] (ii) (b) Write a chemical equation for the reaction between the element and iron. [2 marks] Table 7.2 shows the observation of the reaction between Group 1 elements X , Y and Z with water. Group I element Observation X moves slowly on the water surface with a soft ‘hiss’ sound. A colourless solution that turns red litmus paper blue is formed. X [Proton number =3] Y moves rapidly and randomly on the water surface with a ‘hiss’ sound. A colourless solution that turns red litmus paper blue is formed.. Z burns with a reddish-purple flame, moves very rapidly and randomly on the water surface with ‘hiss’ and ‘pop’ sound. A colourless solution that turns red litmus paper blue is formed.. Table 6.2 Y [Proton number =11] Z [Proton number =19] Based on Table 6.2 (i) Arrange X, Y and Z in descending order of reactivity of Group I elements towards water. Compare and explain the reactivity X and Z with water. [6 marks] (ii) Compare the chemical property of X, Y and Z. Give a reason for your answer. [2 marks] (c) Diagram 6.3 shows the electron arrangement of a molecule XY2. Y X Y Diagram 6.3 Based on Diagram 6.3, write the electron arrangement for atom element X and element Y. Explain briefly how the molecule is formed from atom X and atom Y. Explain the position of element Y in the Period Table of Element. [8 marks] Chemistry Perfect Score Module 2011 16
  • 17. 7. Table 7.1 shows the electron arrangement for atoms W, X and Y. These letters are not the actual symbols of the elements. Element Electron arrangement W 2.4 X Y (a) 2.8.7 2.8.8.1 Table 7.1 State the position of element X in the Periodic Table of Elements. Explain how you determine the group and the period of element X. [4 marks] (b) Atoms W and Y can form chemical bonds with atom X. Explain how the bond is formed between : (i) (ii) Atoms Y and X Atoms W and X [10 marks] (c) Table 7.2 shows physical property of compound P and compound Q. Physical Property Compound P Melting point Compound Q High Low Cannot conduct electricity in molten and solid states Can conduct electricity in molten state or aqueous solution Electrical conductivity Table 7.2 State the type of bond in compound P and compound Q. By choosing one physical property, explain why there is a difference between the property of the compounds. [6 marks] PAPER 2 SECTION C: ESSAY 8 (a) Diagram 8 shows the apparatus set up to determine the empirical formula of oxide of metal M. M is less reactive than hydrogen. Thistle funnel Oxide of metal M Dry hydrogen gas Heat Dilute acid (i) Metal N R Diagram 8 Name a suitable dilute acid and metal N that are used to prepare hydrogen gas. [2 marks] (iii) (iv) Suggest a suitable chemical substance for R and state the function of R. [2 marks] State the example of oxide of metal M. Describe the redoxs reaction that occurs in the combustion tube based on the changes in oxidation number. [6 marks] Chemistry Perfect Score Module 2011 17
  • 18. (b) The information below is about hydrocarbon Y   (i) Empirical formula of Y is CH2 Molar mass of Y = 56 gmol-1 Determine the molecular formula for hydrocarbon Y. [Relative atomic mass of C =12 , H = 1 ] [2 marks] (ii) 9 (a) (i) (ii) Describe an experiment to prepare hydrocarbon Y in the laboratory from its corresponding alcohol. In your answer, include the diagram of the appratus set-up, materials used, and procedure. [8 marks] What is meant by empirical formula? [1 mark] Diagram 9.1 shows the apparatus set-up used to determine the empirical formula of oxide of metal X. Oxide of metal X Dry hydrogen gas → Heat Diagram 9.1 Suggest one suitable oxide of metal X. Write a balanced chemical equation involved. [3 marks] (b) Diagram 9.2 shows the apparatus set-up used to determine the empirical formula of another oxide of metal. Metal Heat Diagram 9.2 (h) Suggest one suitable oxide of the metal. [1 mark] (ii) Based one diagram 9.2, describe how you could determine the empirical formula of the named metal oxide in the laboratory. Your description should include - procedure of experiment - tabulation of results - calculation of the empirical formula [10 marks] (c) A carbon compound contains 84.6% of carbon and 15.4% of hydrogen by mass. The relative molecular mass of this compound is 70. Calculate the molecular formula of this compound. [Relative atomic mass: C, 12; H, 1] [5 marks] Chemistry Perfect Score Module 2011 18
  • 19. CHEMISTRY PERFECT SCORE MODULE SET  1. Electrochemistry 2. Oxidation and Reduction Chemistry Perfect Score Module 2011 19
  • 20. PAPER 2: SECTION A [STRUCTURE] 1 Diagram 1 shows the apparatus set- up for the combination of electrolytic cell and chemical cell. V Magnesium electrode Copper electrode Copper(II) sulphate solution Cell II Cell I Diagram 1 (a) Which cell is the electrolytic cell? (b) ……………………………………………………………………………………..……….……….. [1 mark] Based on Cell I (i) State the negatif terminal of the cell . (ii) …………..…………………………………………………………………………………... [1 mark] Draw the flow of electron in Diagram 1. [1 mark] State the observation at copper electrode. (iii) (c) (d) ……………………………………………………………………………………………… [1 mark] Write half equation for the reaction at copper electrode. …………..………………………………………………………………………………………...…. [2 marks] Based on the Cell II (i) State the energy change in the cell. (ii) ………………………………………………………………………………….…………… [1 mark] What can be observe at the copper(II) sulphate solution? (iii) ….…………………………………………………………………………………………… [1 mark] Explain your answer in d(ii) ……………………………………………………………………..………….…………….. [2 marks] Chemistry Perfect Score Module 2011 20
  • 21. 2 (a) Diagram 2.1 shows the apparatus set-up to investigate the transfer of electrons at a distance between potassium iodide solution and acidified potassium manganate(VII) solution. Diagram 2.1 (i) Name the product formed at electrode R. (ii) ..……….…………................................................................................................................... [1 mark] Complete the half equation for the reaction at electrode S. MnO4 - + ........ H+ + ....... e → Mn2+ + ............... H2O (iii) [1 mark] State the change in oxidation number of manganese and name the process that occurs at S. Change in oxidation number : ……………..........…………………………...........………... (iv) (b) Name of process : ................................................................................................................. [2 marks] Suggest a substance that can replace potassium iodide solution in order to obtain the same reaction. ………….............................................................................................................................. [1 mark] Diagram 2.2 shows the set up of the apparatus to investigate the reactivity of metals J, K and L. The different metals are heated consecutively. Diagram 2.2 Chemistry Perfect Score Module 2011 21
  • 22. Table 2.2 shows the observation of the experiment. Colour of residue Metal Observations Hot Cold Yellow White J Burns brightly K Glows dimly Black Black L Burns with a very bright flame White White Table 2.2 (i) State the name of metal J. (ii) ……….. ………...................................................................................................................... [1 mark] Write a chemical equation for the reaction between metal J and oxygen. (iii) (iv) . ……….……………................................................................................................................ [2 marks] Based on the observation in Table 2.1, arrange metals J, K and L in ascending order of reactivity towards oxygen. ……….. .……......................................................................................................................... [1 mark] A mixture of metal J and oxide of metal L is heated strongly. Predict an observation. Give a reason. ……….................................................................................................................................... ……….. .................................................................................................................................. [2 marks] Chemistry Perfect Score Module 2011 22
  • 23. PAPER 2: SECTION B [ESSAY] 3 (a) Table 3.1 shows the electrical conductivity of two different compounds Compound Propanone (C3H6O) Sodium chloride solution (NaCl) Electrical conductivity Cannot conduct electricity Conduct electricity Table 3.1 Referring to Table 3.1, explain why there is a difference in the electrical conductivity. [4 marks] (b) Diagram 3.1 shows two types of cells. V A B Copper plate D C Zinc plate Copper(II) sulphate solution Cell X Cell Y Diagram 3.1 Compare and contrast cell X and cell Y. Include in your answer the observations and half equations for the reactions at the electrodes in both cells. [8 marks] (c) An experiment is carried out to determine the position of metals silver, L and M in the electrochemical series. Diagram 3.2 shows the results of the experiment. I II III Silver nitrate solution L nitrate solution M Silver nitrate solution M Experimen L Observation  Grey solid deposited  Colourless solution  Grey solid deposited  Light blue solution  No change Diagram 3.2 Chemistry Perfect Score Module 2011 23
  • 24. (i) Based on the results in Diagram 3.2, arrange the electroposivity of metals silver, L and M in ascending order. Explain your answer. [7 marks] (ii) Based on observation in experimen II, suggest one possible metal for M [1 mark] 4 (a) The following is the chemical equation of a redoxs reaction Zn + Pb(NO3)2 → Zn(NO3)2 + Pb Referring to the above chemical equation, (i) (ii) Write half equation for the oxidation and the reduction reactions. [4 marks] Identify substance that is oxidized and reduced. Explain your answer in term of transfer of electrons. [4 marks] (b) Diagram 4 shows two redox reactions that take place in test tubes P and Q. Chlorine water Iron (II) sulphate Test tube P Potassium iodide Test tube Q Diagram 4 (i) State the observations and write the ionic equation for the reaction in test tubes P and Q respectively. [6 marks] (ii) State the name of the product formed in each test tube P and Q (iii) Describe a confirmation test to verify the product in test tube Q [4 marks] [2 marks] Chemistry Perfect Score Module 2011 24
  • 25. PAPER 2: SECTION C [ESSAY] 5 Diagram 5 shows the apparatus set-up and observations for experiments 1 using 1.0 moldm-3 aqueous solution of compound XSO4 and experiment II using 0.0001 moldm-3 aqueous solution of compound XY2. (a) Experiment Apparatus set-up Observation Cathode: Brown solid deposited I Anode: A colorless gas is produced. Cathode: Brown solid deposited II Anode: A colorless gas is produced. The gas relight a glowing splinter. Diagram 5 (i) In both experiment I and experiment II, the product formed at cathode is the same. Using your knowledge of factors affecting the selective discharge of ions at the electrodes, - suggest one possible cation for X2+ ion write the half equation for the reaction at the cathode state the name of the product at cathode [4 marks] (ii) Name the product formed at anode in experiment I. Describe a confirmatory test to identify the gas produced. [3 marks] (iii) Suggest one possible anion for Y- ion in experiment II. Name the product at the anode and explain the formation of the product in the experiment. [6 marks] (b) Pure copper metal is used to make copper wire. Describe how to purify the copper metal using an electrolysis process. Include a labelled diagram in your answer. [7 marks] Chemistry Perfect Score Module 2011 25
  • 26. 6 (a) Diagram 6.1 shows the apparatus set-up to study the effect of metals P and Q on the rusting of iron nail. The results are recorded after three days. Experiment Observation after 3 days Agar-agar solution with potassium hexacyanoferrate(III) and phenolphthalein solution. I   Dark blue precipitate Iron nail rust   Solution turns pink. Iron nail does not rust Iron nail wrapped with metal P Agar-agar solution with potassium hexacyanoferrate(III) and phenolphthalein solution. II Iron nail wrapped with metal Q Diagram 6.1 (i) Name one possible metal for metal P and metal Q [2 marks] (ii) Explain why there is a difference in observation in Experiment I and II. [8 marks] (b) Diagram 6.2 shows a redox reaction between bromine water and iron(II) sulphate solution. Diagram 6.2 (i) Describe the redox reaction that occur in the test tube. Your answer should include the ionic equation and observations. [8 marks] (ii) Based on the oxidation reaction in (b) (i), describe a chemical test to identify the product formed in the test tube. [2 marks] Chemistry Perfect Score Module 2011 26
  • 27. CHEMISTRY PERFECT SCORE MODULE SET  1. Acids and Bases 2. Salts 3. Rate of reaction 4. Thermochemistry Chemistry Perfect Score Module 2011 27
  • 28. PAPER 2 SECTION A [STRUCTURE] 1. Diagram 1 shows four test tubes labeled A,B,C and D which are used to study the relationship between pH value of acid and alkali with the molarity. pH paper A 5 cm3 HCl 0.1 mol dm-3 B 5 cm3 HCl 0.01 mol dm-3 C 5 cm3 NaOH 0.1 mol dm-3 D 5 cm3 NaOH 0.01 moldm-3 Diagram 1 (a) Determine which solution has (i) highest pH value? (ii) …………….……………………………………………………………………………........ [1 mark] lowest pH value? ………………………………………………………………………………………............. [1 mark] (b) If the hydrochloric acid in test tube B is replaced with 5 cm3 of 0 .1 mol dm-3 ethanoic acid, predict the pH value of the solution. Explain your answer …………………………………………………………………………………………………………...……….. …. …………………………………………………………………………………………………… ………………………………………………………………………………………………………. [3 marks] (c) Excess of magnesium powder is added to 5 cm3 of 0.1moldm-3 hydrochloric acid in test tube A (i) Name the products formed. . (ii) (iii) ……...……………………………………………………………………………………….. [1 mark] Write an ionic equation for the reaction in test tube A ……………………………………………………………………………………………… [1 mark] Calculate volume of hydrogen gas released at room conditions in test tube A [1 mol of gas occupies 24 dm3 at room conditions] [3 marks] Chemistry Perfect Score Module 2011 28
  • 29. (d) If the solution in test tube C is added to lead(II) nitrate solution. State the observation from the reaction. …….…………………………………………………………………………………………………. [1 mark] 2. (a) Diagram 2.1 shows the pH value of glacial ethanoic acid in solvent P and solvent Q respectively. 7.0 4.8 Glacial ethanoic acid + solvent P Glacial ethanoic acid + solvent Q Diagram 2.1 (i) Give one example of each solvent P and solvent Q. Solvent P: ………………………………………………………….………...……………… Solvent Q: …………………………………………………………………………………. [2 marks] (ii) (iii) If magnesium ribbon is added into beaker containing glacial ethanoic acid and solvent P, what can be observed? ……………………………………….……………………………………………………… [1 mark] Explain why ethanoic acid in solvent P and solvent Q has different the pH value. ….…………………………………………………………………………………………… ….…………………………………………………………………………………………… ….…………………………………………………………………………………………… ...…………………………………………………………………………………………….. [3 marks] (b) Diagram 2.2 shows the concentration of hydrochloric acid decrease when water is added into beaker J. Add water 250 cm3 of 0.04 moldm-3 hydrochloric acid 100 cm3 of 0.5 moldm-3 hydrochloric acid Beaker J Beaker L Diagram 2.2 Chemistry Perfect Score Module 2011 29
  • 30. (i) When water is added into beaker J, what happen to the pH value of the hydrochloric acid? Give reason to your answer. ….…………………………………………………………………………………………… .……………………………………………………………………………………………… [2 marks] (ii) Calculate the volume of hydrochloric acid in beaker J that is needed to prepare hydrochloric acid in beaker L. [2 marks] 3. A student carried out an experiment to investigate the properties of three solutions. Table 3 shows the results of the experiments. Test tube Set-up of apparatus P Red litmus Paper Ammonia gas dissolved in water Observation Q Red litmus Paper Ammonia gas dissolved in propanone R Magnesium Hydrogen chloride gas dissolved in water The red litmus paper turned blue. (a) Table 3 What is meant by strong alkali? (b) ....................................................................................................................................... [1 mark] What is the property of the solution in test tube P? (c) ....................................................................................................................................... [1 mark] What are the types of particles that exist in the test tubes P and Q? Particles in the test tube P: .......................................................................................... Particles in the test tube Q: ......................................................................................... [ 2 marks] (d) Is there any changes of colour of the litmus paper in test tube Q? Explain why. ...................................................................................................................................... ...................................................................................................................................... [ 2 marks] Chemistry Perfect Score Module 2011 30
  • 31. (e) (i) What can be observed in test tube R? ....................................................................................................................................... [1 mark] (ii) Write a chemical equation for the reaction in test tube R. ....................................................................................................................................... [2 mark] (iii) 2.4 g of magnesium is reacted completely with the solution in test tube R. Calculate the volume of the hydrogen gas produced at room condition [Relative atomic mass: Mg,24; 1 mol of gas occupies 24 dm3 at room conditions] [ 2 marks] 4. Diagram 4 shows a series reaction of copper compound. Copper(II) nitrate Sodium carbonate Copper(II) carbonate Copper(II) oxide Copper(II) sulphate a) Diagram 4 Copper(II) nitrate solution reacts with sodium carbonate solution to form copper(II) carbonate precipitate. (i) What is the colour of Copper(II) carbonate? ………………………………………………………………………………………………............. [1 mark] (ii) Name the reaction. ............................................................................................................................................................. b) [1 mark] Heating of copper(II) carbonate produces copper(II) oxide and gas R. i) Name gas R. ……………………………………………………………………………………………….. [1 mark] ii) Write the chemical equation of the reaction. ......................................................………………………………………………………...................... [2 marks] Chemistry Perfect Score Module 2011 31
  • 32. (iii) c) Draw a labeled diagram for the heating of copper(II) carbonate to produce copper(II) oxide and gas R. In your diagram show how gas R is tested. [2 marks] Copper(II) carbonate reacts with hydrochloric acid to produce copper(II) chloride. The chemical equation is shown below. CuCO3 + 2HCl → CuCl2 + CO2 + H2O 12.4 g copper(II) carbonate reacts completely with excess hydrochloric acid. Calculate the mass of copper(II) chloride. [Relative atomic mass: Cu = 64, C = 12, O=16 , Cl = 35.5, H=1) [2 marks] 5. Three experiments were conducted to investigate the factors affecting the rate of reaction. The results are shown in the Table 5 Temperature / 0C Time taken for all the magnesium to dissolve/s 0.4g magnesium ribbon and 50 cm3 1 moldm-3 hydrochloric acid 30 100 0.4g magnesium powder and 50 cm3 1 moldm-3 hydrochloric acid 30 Experiment I II III (a) (b) Reactants 60 0.4g magnesium ribbon and 50 cm3 1 moldm-3 hydrochloric acid and copper(II) 30 45 sulphate solution Table 5 Write a chemical equation to show the reaction between magnesium and hydrochloric acid. ………..……………………………………………………………………………………………… [2 marks] Calculate the number of mole of [Relative atomic mass of Mg = 24] (i) Magnesium [1 mark] (ii) Hydrochloric acid [1 mark] (c) If hydrochloric acid used is excess, calculate the maximum volume of hydrogen gas produce at room temperature and pressure. [1 mole of gas occupies the volume of 24 dm3 at room temperature and pressure] [2 marks] Chemistry Perfect Score Module 2011 32
  • 33. (d) Calculate the average rate of reaction for Experiment I and II. [2 marks] (e) What is the purpose of using copper(II) sulphate? ……………….……………………………………………………………………………………… [1 mark] (f) The factor that affects the rate of reaction in this experiment is total surface area and the use of catalyst. State two other factors that affect the rate reaction in this experiment. ……………………………………………………………………………………………………… ……..……………………………………………………………………………………………….. [2 marks] 6. An experiment is carried out to determine the heat of displacement for the reaction between copper(II)  sulphate solution and excess zinc powder. 50.0 cm3 of 0.5 mol dm 3 copper(II) sulphate solution is poured into a plastic cup. The initial temperature of the solution is recorded after 5 minutes. 5 g of excess zinc powder is added into a plastic cup. The mixture is stirred and the highest temperature is recorded. The following data is obtained: Initial temperature of copper(II) sulphate solution Highest temperature of the mixture reached = 28.0 0C = 38.0 0C [Relative atomic mass : Cu,64; S,32; O,16; Zn, 65; Specific heat capacity of water : 4.2 Jg1 0C1] (a) Based on the experiment, what is meant by the heat of displacement? (b) ………………….……………………………...……………………………………………………. [1 mark] Write an ionic equation for the reaction. (c) ……………………………………………………………………………………………………….. [1 mark] State two observations in the experiment. (i) …………………………………………………………………………………………….…...… (ii) ………………………………………………………………………………………………...... [2 marks] (d) Calculate, (i) the heat released [1 mark] (ii) the number of moles of copper (II) sulphate reacted [1 mark] Chemistry Perfect Score Module 2011 33
  • 34. (iii) the heat of displacement [2 marks] (e) Why excess zinc powder is used in this experiment? (f) ……...………………………………………………………..………………………………………. [1 mark] Draw the energy level diagram for the reaction. [2 mark] 7. 50 cm3 1.0 mol dm-3 sodium hydroxide solution is poured into a polystyrene cup. The polystyrene cup is then placed into a beaker as shown in Diagram 5 Beaker Polystyrene cup Sodium hydroxide solution + hydrochloric acid Diagram 5 The initial temperature of sodium hydroxide solution in the polystyrene cup is measured. 10 cm3 of hydrochloric acid is added to the 50 cm3 sodium hydroxide and the temperature increase is recorded. Then, the heat energy released is calculated. The experiment is repeated by adding different volumes of hydrochloric to the 50 cm3 of sodium hydroxide. The results are tabulated as shown below. Volume of sodium hydroxide solution / cm3 50 50 50 50 50 50 50 (a) Volume of hydrochloric acid added / cm3 10 20 30 40 50 60 70 Heat energy released / kJ 1.1 2.2 3.4 4.5 5.6 5.6 5.6 Plot a graph heat energy released against volume of hydrochloric acid added. [3 marks] (b) (i) Based on the graph, determine the volume of hydrochloric required for complete neutralisation with 50 cm3 1.0 mol dm-3 sodium hydroxide [1 mark] (ii) From your answer in (b) (i), calculate the concentration of hydrochloric acid used in moldm-3. [2 marks] Chemistry Perfect Score Module 2011 34
  • 35. Chemistry Perfect Score Module 2011 35
  • 36. (c) Why the content in the polystyrene cup has to be stirred continuously throughout the experiment? ……………………………………………………………………………………………………….. [1 mark] (d) Explain briefly why the heat released becomes constant after 50 cm3 of hydrochloric acid is added. ……………………………………………………………………………………………………… (e) ……………………………………………………………………………………………............... [1 mark] (i) Calculate the heat energy released when 1 mole of sodium hydroxide is neutralized by hydrochloric acid. [1 mark] (ii) (f) Draw the energy level diagram for the reaction that occurred in the polystyrene cup. [2 marks] In another experiment, 50 cm3 1.0 mol dm-3 sodium hydroxide solution is added with 50 cm3 1.0 mol dm-3 ethanoic acid. (i) Predict the heat energy released (ii) ………………………………………………………………………………………………. [1 mark] Give a reason for your answer in (f) (i). ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… [2 marks] Chemistry Perfect Score Module 2011 36
  • 37. PAPER 2: SECTION B [ ESSAY] 8. A student has carried out an experiment to construct an ionic equation for the formation of lead(II) iodide. Seven test tubes of the same size were labelled 1 to 7. A fixed volume of 5.0 cm3 of 1.0 mol dm-3 potassium iodide solution was placed in each test tube. 0.5 cm3 of 1.0 moldm-3 lead(II) nitrate solution was added into test tube 1, 1.0 cm3 into test tube 2 and so on until 3.5 cm3 was added into test tube 7. The heights of the precipitate formed in each test tube were measured. The results are shown in Table 6. Test tube Volume of 1.0 moldm-3 lead(II) nitrate solution/ cm3 Height of precipitate /cm 1 2 3 4 5 6 7 0.5 1.0 1.5 2.0 2.5 3.0 3.5 1.1 2.2 3.4 4.4 5.5 5.5 5.5 Table 8 (a) Based on Table 8, (i) Plot a graph of the height of the precipitate against volume of lead(II) nitrate solution on the graph paper provided . [3 marks] (ii) Determine the volume of lead(II)nitrate solution that had reacted completely with 5.0 cm3 of 1.0 moldm-3 potassium iodide. [1 mark] (iii) Using the volume obtained in (a) (ii), calculate the number of moles of lead(II) ions and iodide ions that are required for the formation of lead(II) iodide. Then, calculate the number of moles of iodide ions that has reacted with 1 mol of lead(II) ions. [4 marks] (iv) Write the ionic equation for the formation of lead(II) iodide. [2 marks] (b) By referring to test tube 1, 5 and 7 in Table 8, state the ions that exist in the solution. Explain your answer. [10 marks] Chemistry Perfect Score Module 2011 37
  • 38. 9. (a) (i) The rate of reaction is important in industries and in our everyday lives. State the four factors that affect the rate of reaction. (i) (b) [4 marks] What are the conditions required for the production of ammonia in Haber Process? [3 marks] A student carried out two experiments to investigate the effect of concentration on the rate of reaction. Diagram 9.1 shows the set-up of apparatus of the experiments. Experiment Set-up of apparatus Excess hydrochloric acid 0.2 mol dm-3 I Water Air 0.2 g calcium carbonate powder Excess hydrochloric acid 0.5 mol dm-3 II Water Air 0.2 g calcium carbonate powder Diagram 9.1 Table 9.2 shows the result of the experiments. Time /s 0 30 60 90 120 150 180 210 0.00 5.00 10.00 14.20 18.00 21.30 24.00 26.00 0.00 10.00 17.00 23.00 25.00 26.00 26.00 26.00 3 Volume of gas of Experiment I /cm Volume of gas of Experiment II /cm3 Table 9.2 (i) (ii) Plot the graph of the volume of carbon dioxide gas against time for Experiment I and II on the same axes on the graph paper provided . [4 marks] Calculate the average rate of reaction for Experiment I and II. [4 marks] (iii) Compare the rate of reaction between Experiment I and Experiment II. Explain the differences in the rate of reaction with reference to the collision theory. [5 marks] Chemistry Perfect Score Module 2011 38
  • 39. Question 9 (b) (i) Chemistry Perfect Score Module 2011 39
  • 40. PAPER 2: SECTION C [ESSAY] 10. Table 10 shows the data from Experiment I and Experiment II that were carried out to study the rate of reaction of magnesium ribbon with two acids, X and Y . Experiment I II Reactants Excess of magnesium ribbon and 50 cm3 of acid X 1.0 mol dm-3 Excess of magnesium ribbon and 50 cm3 of acid Y 1.0 mol dm-3 Products Magnesium chloride and hydrogen gas Magnesium sulphate and hydrogen gas Table 10 (a) (i) State the name of the acid X and Y. Write the chemical equation for the reaction of this acid with magnesium. [3 marks] (ii) Calculate the number of mol of acid X or acid Y that react with excess magnesium ribbon. [1 mark] (iii) Based on this experiment what is meant by the rate of reaction? [1 mark] (b) (i) At the same axis, sketch the graph of volume of gas against time for experiment I and experiment II. [ 2 marks] (ii) Compare the rate of reaction in experiment I and II . Explain your answer based on collision theory. [5marks] 11. a) b) (c) Describe one laboratory experiment to conduct the Experiment I or Experiment II to determine the rate of reaction. Your answer should include the following : A labeled diagram showing the apparatus set-up Procedures of the experiment A table to collect the data [8 marks] A student with a wet T-shirt entered an air-conditioned room. After half an hour, the student was shivering with coldness. Explain this pheomena with reference to changes in physical state and energy change involved. [2 marks] Table below shows the molecular formula and heat of combustion for ethanol and propanol. Alcohols Molecular Formula Heat of Combustion, H Ethanol C2H5OH - 1,376 kJ / mol Propanol C3H7OH - 2,015 kJ / mol Based on the information above, (i) Write the thermochemical equation for the combustion of ethanol. [2 marks] (ii) Compare the heat of combustion between ethanol and propanol. Explain your answer. [4 marks] (iii) Describe an experiment to determine the heat of combustion of ethanol. Include the following in your answer :  Set-up of apparatus  Materials and apparatus  Procedure  Results and calculation [12 marks] Chemistry Perfect Score Module 2011 40
  • 41. 12. (a) What is meant by exothermic and endothermic reaction? Explain the changes in energy content of the reactants and products for both of the reactions. [4 marks] (b) Diagram represent the energy level diagram for a chemical reaction Energy C + D ΔH= + x kJ / mol A + B State four information that can be obtained from the above diagram. [4 marks] (c) Reaction I and II below are the thermochemical equation for the heat of precipitation. Reaction I : AgNO3 + NaCl → AgCl + NaNO3  H = - 210 kJmol-1 Reaction II : AgNO3 + KCl → AgCl + KNO3  H = - 210 kJmol-1 Explain why the value of heat of precipitation in reactions I and II are the same. [4 marks] (d) Ca2+(aq) + CO32- (aq) → CaCO3 (s) ∆H = + 12.6 kJmol-1 Describe a laboratory experiment to determine the heat of reaction for the above reaction. In your answer, include the following :  chemicals required  procedures of the experiment  results and calculation involved [8 marks] Chemistry Perfect Score Module 2011 41
  • 42. 13. Diagram 13.1 shows the flow chart for the preparation of magnesium carbonate and magnesium sulphate through reaction I and II. Magnesium nitrate Reaction I Reaction II Magnesium carbonate Magnesium sulphate Diagram 13.1 a) (i) Based on the Diagram 13.1 , classify the above salts to soluble salt and insoluble salts. [2 marks] (ii) State the reactant used for the preparation of magnesium carbonate from magnesium nitrate in reaction I and II [2 marks] (iv) Describe the preparation magnesium carbonate from magnesium nitrate in the laboratory through reaction I [6 marks] b) Diagram 13.2 shows conversion of salt X when it heated strongly and dissolved in water. The solution formed is tested with sodium hydroxide solution, NaOH. Salt X solid Metal oxide ∆ + Brown gas + Colourless gas H2O Salt X solution NaOH solution A white precipitate soluble in excess NaOH. Diagram 13.2 Based on the information in the Diagram 13.2, (i) Identify an anion that is present in salt X. Describe a chemical test to verify the anion. (ii) Identify three cations that are possible present in salt X solution. Describe chemical test to verify the cations. [4 marks] [6 marks] Chemistry Perfect Score Module 2011 42
  • 43. CHEMISTRY PERFECT SCORE MODULE SET 1. 2. 3.  Carbon Compounds Manufactured Substances in Industry Chemicals for Consumers Chemistry Perfect Score Module 2011 43
  • 44. PAPER 2: SECTION A [STRUCTURE] 1. Diagram 1 shows the structural formula of compound X. Diagram 1 (a) Compound X is an unsaturated hydrocarbon. What is the meaning of unsaturated hydrocarbon? ………………........……………………………………...................................................................... [2 marks] (b) State the homologous series for compound X. …………………………………………………………...................................................................... [1 mark] (c) Name the compound X. …………………………………………………………....................................................................... [1 mark] (d) At 180oC and in the presence of nickel as catalyst, compound X can be changed into saturated hydrocarbon compound. (i) Name the reaction. ……………………………………………………………………….............................................. [1 mark] (ii) Draw the structural formula for the compound formed. [1 mark] (e) Compound X burns completely in excess oxygen. (i) Write a balanced chemical equation for the complete combustion of X. ....................................................................................................................................................... [2 marks] (ii) 2.1 g of compound X undergoes complete combustion at room conditions. Calculate the volume of carbon dioxide gas released. [1 mol of gas occupies 24 dm3 at room conditions; Relative atomic mass: H = 1; C = 12] [2 marks] Chemistry Perfect Score Module 2011 44
  • 45. 2. Diagram 2 shows a series of reactions. Compound P with the molecular formula C2H6O, can be prepared through fermentation of glucose solution. Glucose Compound P C2H6O Reaction I Compound Q Reaction II Compound R Diagram 2 (a) Name the compound P. ......………………………………………………………………………............................................ [1 mark] (b) State the functional group of compound P. …………………………………………………………........................................................................ [1 mark] (c) In the reaction I, compound Q is produced when an acidified potassium dichromate (VI) solution is added into a test tube containing compound P. (i) Name the reaction I. ......……………………………………………………………………….................................... [1 mark] (ii) State one observation for this reaction. ...........................……………………………………………………………………….............. [1 mark] (iii) Draw the structural formula of compound Q. [1 mark] (d) In the reaction II, compound R is formed when compound P reacts with compound Q in the presence of concentrated sulphuric acid. (i) Name the reaction II. (ii) ......………………………......................……………………………………………….............. [1 mark] Name the compound R. (iii) ........……………………………………………………………………….................................. [1 mark] Give one special physical property of compound R. .......……………………………………………………………………….................................. [1 mark] (iv) Write the chemical equation for the reaction II. ..………………………………………………………………………........................................ [2 marks] Chemistry Perfect Score Module 2011 45
  • 46. 3. (a) Diagram 3.1 shows the manufactured of ammonia and sulphuric acid. Process I Ammonia Ammonium sulphate Process II Sulphuric acid Diagram 3.1 Based on Diagram 3.1, answer the following questions. (i) State the name of Process I. (ii) (iii) …………………….……………………………………………………………………………… [1 mark] Write the chemical equation for the reaction to produce ammonia in Process I. ..…………………………..………………………….…………………………………………… [2 marks] In Process II, sulphur dioxide is reacted with oxygen to produce sulphur dioxide. State the temperature and the catalyst used in this reaction. …………………………………………………………………….……………………………… (iv) ……………………………………………………………………………………………………. [2 marks] State one use of ammonium sulphate. …………….……………………………………………………………………………………… [1 mark] (b) Diagram 3.2 shows a structural formula of a polymer. Diagram 3.2 (i) State the name of the polymer in Diagram 3.2 (ii) …………………………………………………………………………………………………… [1 mark] Draw the structural formula for the monomer in Diagram 3.2 [1 mark] (c) Bronze is an alloy of copper. Draw a labeled diagram to show the arrangement of atoms in bronze. [2 marks] Chemistry Perfect Score Module 2011 46
  • 47. 4. The following equation shows how soap can be prepared. palm oil + potassium hydroxide → substance Z + soap (a) (i) State the name of substance Z. …………………………………………………………………………………………………………… [1 mark] (ii) State the name of the process in the above reaction. …………………………………………………………………………………………………………… [1 mark] (iii) Explain why potassium chloride is added during the preparation of soap. …………………………………………………………………………………………………………… [1 mark] (b) Two cleaning agents, X and Y, are used to wash clothes in river water and sea water. The results obtained are shown in Table 4 below. Cleaning agent River water Sea water X Does not form scum Does not form scum Y Does not form scum Forms scum Table 4 (i) State the type of cleaning agents X and Y. X: ……………………………………………………………………………………………………….. Y: ………………………………………………………………………………………………………… [2 marks] (ii) State the name of the scum formed if Y is sodium stearate. …………………………………………………………………………………………………………… [1 mark] (iii) State the two ions present in sea water that cause the formation of scum in Y. …………………………………………………………………………………………………………… [2 marks] (iv) Give one disadvantage of using the cleaning agent X. …………………………………………………………………………………………………………… [1 mark] Chemistry Perfect Score Module 2011 47
  • 48. PAPER 2: SECTION B [ESSAY] 5. (a) A hydrocarbon M, consists of 85.7% of carbon and X% of hydrogen by mass. The relative molecular mass of M is 56. [Relative atomic mass: C = 12; H = 1] (i) What is the value of X. (ii) Determine the empirical formula and molecular formula of hydrocarbon X. (iii) Draw the structural of the two isomers of hydrocarbon M. Write the names for each isomer (iv) Compound M burns with sootier flames as compared to butane. Explain and prove. [1 mark] [5 marks] [4 marks] [3 marks] (b) Natural rubber is a natural polymer. (i) Give another two examples of natural polymer. [2 marks] (ii) Name and draw the structural formula of the monomer of natural rubber. [2 marks] (c) The tyres of aircrafts are made from vulcanised rubber. (i) What is vulcanised rubber? [1 marks] (ii) Explain why vulcanised rubber is more elastic than unvulcanised rubber. [2 marks] 6. (a) (b) Food preservatives are substances added to food so that the food can be kept for longer periods for time. Using two suitable examples, explain how they work as preservative. [4 marks] The following is the information about a child.  2 years old  High fever  Whooping cough Based on the information above, (i) Name two examples of modern medicine that can be used to treat the child . (c ) [2 marks] (ii) State two precautions that should be taken by the parents while giving the medicine to their child. [2 marks] (iii) Explain the effect if the precautions states in (b)(ii) are not followed properly. [2 marks] Table 6 shows the food additives that are added to a certain food by two chefs. Chef Wan Turmeric Sugar, salt and spice Garlic Chef Koh Tartrazine Monosodium glutamate Ascorbic acid Table 6 Based on Table 6, categorise the food additives. Include in your answer the function of each type of food additives and the disadvantages of using any two food additives. [10 marks] Chemistry Perfect Score Module 2011 48
  • 49. PAPER 2: SECTION C [ESSAY] 7. Diagram 7 shows the flow chart for the industrial manufacture of sulphuric acid and the production of three types of fertilizer. Step 1 Sulphur Step II Sulphur dioxide Substance X Step III Step IV Sulphuric acid Oleum + Ammonia Fertiliser Y Diagram 7 (a) (i) Based on step I to step IV , describe briefly the industrial production of sulphuric acid. [4 marks] (ii) (b) Write a chemical equation for the reaction between sulphuric acid and ammonia to produce fertilizer Y. [2 marks] Table 7 shows the diameter of the dent formed in an experiment to compare the hardness of copper and bronze. Based on Table 7, compare the hardness between copper and bronze, explain why ? Material Copper Bronze Diameter /cm 1.0 0.5 Table 7 [4 marks] (c) 8. The iron window frame of Encik Azman’s house rusts after several years but the steel window frame of Encik Tarmizi’s house does not rust. By using suitable examples, describe a laboratory experiment to compare the resistant to rust of alloy compared to pure metal. Include the following in your answer:  Procedure  Results  Conclusion [10 marks] (a) Table 8 shows the result of two sets of experiment to investigate the coagulation of latex. Set I II Type of solution Observation Latex + solution X Latex + solution Y Latex coagulate very fast Latex does not coagulate Table 8 (i) Suggest one possible substance for solution X. and Y (ii) Explain the process of coagulation of latex in set I (iii) Explain why latex does not coagulate in set II [2 marks] [4 marks] [2 marks] Chemistry Perfect Score Module 2011 49
  • 50. (b) Diagram 8 shows how compound Q is formed from alkene W. Alkene W + H2O Compound Q Diagram 8 (i) Name the homologous series of compound Q. (ii) State two chemical properties of compound Q. [1 mark] [2 marks] (iii) By using a compound Q with number of carbon atom per molecule more than one, describe an experiment to convert compound Q to alkene. Your answer should consist of the following:  Procedure of the experiment  A labelled diagram showing the apparatus set-up  The test to confirm the product is alkene [9 marks] Chemistry Perfect Score Module 2011 50
  • 51. CHEMISTRY PERFECT SCORE MODULE SET  1. PAPER 3 SET 1 2. PAPER 3 SET 2 3. PAPER 3 SET 3 Chemistry Perfect Score Module 2011 51
  • 52. PAPER 3 SET 1 1. Diagram 1.1 shows the set-up of apparatus for an experiment to compare the hardness of a metal and its alloy. Thread Weight Meter ruler Retort stand Steel ball bearing Material X Diagram 1.1 A steel ball bearing is taped onto the material X block using cellophane tape. A weight of 1 kilogram is dropped at a height of 50 cm to hit the ball bearing. The diameter of the dent made on the material X block is measured. The experiment is repeated by replacing material X block with material Y block. Table 1.1 shows the view of the dents made on the material X and Y. Experiment Material X Material Y I Diameter: ................. Diameter: ................. Diameter: ................. Diameter: ................. Diameter: ................. Diameter: ................. II III Table 1.1 Chemistry Perfect Score Module 2011 52
  • 53. (a) (i) (ii) Using a ruler, measure the diameters of the dents made on material X and Y. Record all the diameters of the dents in table 1.1. [3 marks] Construct a table to record the diameters of the dents and average diameter on material X and material Y. [3 marks] (b) State one observation that can be obtained from this experiment. ...................................................................................................................................................................... …………………………………………………………………………………………………………….. [3 marks] (c) Based on the average diameter of the dents on material X and Y, state the inference that can be make. ...................................................................................................................................................................... …………………………………………………………………………………………………………….. [3 marks] (d) State the operational definition for the hardness of alloy. ...................................................................................................................................................................... …………………………………………………………………………………………………………….. [3 marks] (e) Explain why there is difference in diameter of dents on material X and Y. ...................................................................................................................................................................... …………………………………………………………………………………………………………….. [3 marks] (f) Suggest a suitable material for X and Y. ...................................................................................................................................................................... [3 marks] (g) State the hypothesis for this experiment. ...................................................................................................................................................................... …………………………………………………………………………………………………………….. [3 marks] (h) Complete table 1.2 based on the experiment. Name of variables (i) Manipulated variable: Action to be taken (i)The way to manipulate variable: (ii) Responding variable: (ii) What to observe in the responding variable: (iii) Controlled variable: (iii) The way to maintain the control variable: Table 1.2 Chemistry Perfect Score Module 2011 [3 marks] 53
  • 54. 2. Diagram 2 shows the set-up of apparatus to investigate the effect of other metals X, Y and Z on the rusting of iron. A mixture of jelly solution, potassium hexacyanoferrate(III) solution and phenolphthalein were used as medium in each test tube. The observations were recorded after one day. Test tube A Iron nail coiled with metal X High intensity of blue colour. Test tube B Iron nail coiled with metal Y High intensity of pink colour Test tube C Iron nail coiled with metal Z Low intensity of pink colour Test tube D Iron nail Low intensity of blue colour Diagram 2 (a) State the inference for the observation in test tube A, B, C and D. Test tube Inference A B C D [3 marks] (b) Based on this experiment, explain why there is a difference in the observation between test tube A and B. ………………………………………………………………………………………………………… ………………………………………………………………………………………………………… [3 marks] Chemistry Perfect Score Module 2011 54
  • 55. (c) State the hypothesis for the experiment. ………………………………………………………………………………………………………… ………………………………………………………………………………………………………… [3 marks] (d) Based on this experiment state: (i) The manipulated variable: ………………………………………………………………………... (ii) The responding variables:…………………………………………………………………………. (iii) The constant variables:………………………………………………………………………….... [3 marks] (e) State the operational definition for the rusting of iron nail. ………………………………………………………………………………………………………… ………………………………………………………………………………………………………… [3 marks] (f) Based on this experiment classify the metals that can provide sacrificial protection and metal cannot provide sacrificial protection to iron. [ 3 marks] (g) Observation in test tube D is recorded after two days. Compare the observation for the experiment after it left for one day and two days. Explain your answer. After one day After two days . ………………………………………………………………………………………………………… ………………………………………………………………………………………………………… [3 marks] Chemistry Perfect Score Module 2011 55
  • 56. ESAY / PLANNING 3. Different type of alcohols produces different heat of combustions. When the number of carbon per molecule of alcohol increases the heat of combustion increases. Table 3.1 shows the heat of combustion of ethanol, propanol and butanol. Alcohol Ethanol Propanol Butanol Heat of combustion/ kJ mol-1 -1376 -2016 -2678 Molecular formula C2H5OH C3H7OH C4H9OH Table 3.1 Plan a laboratory experiment to compare the heat of combustion of the alcohols. Your planning must include the following aspects: (a) Statement of the problem (b) All the variables (c) Hypothesis (d) List of materials and apparatus (e) Procedure (f) Tabulation of data [17 marks] PAPER 3 SET 2 1. A student carried out an experiment to determine the end-point for the titration of 25.0 cm3 of 1.0 mol dm-3 sodium hydroxide solution with hydrochloric acid. Phenolphthalein is used as the acid-base indicator. Table 1 shows the three titrations that were conducted and the magnification of the burette readings. I Titration No. II III 13 Initial burette reading 1 hydrochloric acid hydrochloric acid 26 hydrochloric acid 14 27 2 ……………………….. ………………………….. 38 13 Final burette reading …………………………….. hydrochloric acid 26 7 hydrochloric acid hydrochloric acid 39 14 27 …..…………………… ….…………………… …..……………………. Table 1 Chemistry Perfect Score Module 2011 56
  • 57. (a) Record the burette readings for the three titrations in the spaces provided in Table 1. [3 marks] (b) Construct a table and record the initial burette reading, final burette reading and the volume of acid used for each titration. [3 marks] (c) Calculate the molarity of the hydrochloric acid used in the experiment. [ 3 marks] (d) State the operational definition for the neutralization of sodium hydroxide solution in this experiment. …………………………………………………………………………………………………………… ………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………. [3 marks] (e) The experiment is repeated by replacing hydrochloric acid 1.0 mol dm-3 with sulphuric acid 1.0 mol dm-3. (i) Predict the volume of sulphuric acid needed to neutralise the sodium hydroxide solution. …..…….............................................................................................................................................. (ii) Explain your answer for (e) (i). ……................................................................................................................................................. ……................................................................................................................................................. [3 marks] (f) Table 1 shows the results of an experiment to investigate the pH values of acids. Solution Hydrochloric acid, 1.0 mol dm-3 Ethanoic acid, 1.0 mol dm-3 Table 1 For this experiment, state (i) The manipulated variable pH value 2.0 5.0 (ii) ......................................................................................................................................................... The responding variable (iii) ……................................................................................................................................................. The fixed variable ……................................................................................................................................................. [3 marks] Chemistry Perfect Score Module 2011 57
  • 58. (g) State one hypothesis for this experiment. …………………………………………………………………………………………………………… ………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………. [3 marks] (h) Classify the following substances into substances with pH value less than 7 and pH value more than 7. Ethanoic acid Ammonia solution Barium hydroxide Nitric acid [3 marks] 2. Diagram 2.1 shows the apparatus set up for the preparation of ester in the laboratory. water in water out Mixture of alchohol + carboxylic acid and a few drops of concentrated sulphuric acid heat Table 2.1 show some examples of the types of alcohol and carboxylic acid used to prepare ester. Alcohol Carboxylic Acid Observation Methanol Ethanoic acid Sweet pleasant smell Ethanol Propanoic acid Sweet pleasant smell Propanol Methanoic acid Sweet pleasant smell Table 2.1 (a) State one inference for this experiment. ………………………………………………………………………………………………………… ………………………………………………………………………………………………………… …………………………………………………………………………………………………….… [3 marks] Chemistry Perfect Score Module 2011 58
  • 59. (b) Construct a table to show the alcohols and carboxylic acid from table 2.1 and the esters formed. [3 marks] (c) Propyl butanoate is an ester that is formed from the reaction between an alcohol and carboxylic acid. Name the alcohol and carboxylic acid needed to prepare the ester. Alcohol: ..................................................................................................................................... Carboxylic acid: ........................................................................................................................ [3 marks] (d) Table 2.2 shows the observation for an experiment to differentiate between alkanes and alkenes. Experiment Hexane Hexene Added with bromine water No change Brown bromine decolourised Added with acidified potassium No change Purple solution decolourised manganate (VII) solution Table 2.2 (i) State the variables for this experiment: Manipulated variable.:..................................................................................................... Responding variable..:.................................................................................................... (ii) (iii) (iv) Fixed variable ........................................................................................................................ [3 marks] State one hypothesis for this experiment. ….…………………………………………………………………………………………… …...…………………………………………………………………………………………… [3 marks] Give the operational definition for alkene in this experiment. ….…………………………………………………………………………………………… …...…………………………………………………………………………………………… [3 marks] Hexene can also be differentiated from hexane with sootiness of flame when burnt. Predict which substance will produce more soot when burnt. Explain your answer. ….…………………………………………………………………………………………… …...…………………………………………………………………………………………… ………………………………………………………………………………………………. [3 marks] Chemistry Perfect Score Module 2011 59
  • 60. 3. Diagram 3 shows the set-up of apparatus used to investigate the cleansing action of a cleaning agent on a piece of cloth stained with oil. Experiment Apparatus Observation I Oil stained remains II Oil stained remains Based on the above diagram, plan one laboratory experiment to compare the effectiveness of cleaning agents A mad B on cleansing action in hard water. Your planning should include the following aspects: (a) Aim (b) All the variables (c) Statement of the hypothesis (d) List of substances and apparatus (e) Procedure of the experiment (f) Tabulation of data [17 marks] Chemistry Perfect Score Module 2011 60
  • 61. SET 3 1. Diagram 1.1 shows the set-up of apparatus and thermometer reading for the experiment to compare the heat of combustion of four alcohols, methanol (CH3OH), ethanol (C2H5OH), propanol (C3H7OH) and butanol (C4H9OH). The initial and final mass of the spirit lamp containing alcohol is weighed and recorded. The alcohols is used to heat 200 cm3 of water . Wind shield Thermometer Copper tin Water Methanol Initial temperature:......................... Wind shield Thermometer Copper tin Water Methanol Highest temperature:................... Diagram 1.1 (a) Based on Diagram 1.1, (i) record the initial and highest reading of the thermometer in the spaces provided. [3 marks] (ii) State one observation .......................................................................................................................................................[ 3 marks] (ii) Give one inference based on the observation in (a)(ii). ....................................................................................................................................................... [3 marks] Chemistry Perfect Score Module 2011 61
  • 62. (b) Diagram 1.2 shows the initial and final reading of the electronic balance for the mass of spirit lamp before burning and after burning of four alcohols. Alcohol Initial reading (g) Final reading (g) Mass of alcohol used (g) Methanol ON OFF 354.9548 g ON OFF 353.4012 g 342.0201 g ON OFF 339.7892 g ON OFF 364.4303 g ON OFF 360.8702 g ON OFF 332.9891 g ON OFF 328.9790 g Ethanol OFF ON Propanol Butanol Diagram 1.2 Based on Diagram 1.2, (i) state the mass of the alcohols used in space provided into two decimal places. [ 3 marks] (ii) Tabulate the initial mass, final mass and mass of alcohol used for the four alcohols in this experiment. [3 marks] Chemistry Perfect Score Module 2011 62
  • 63. (c) Calculate the heat of combustion of methanol. [Specific heat capacity of water = 4.2 J g-1 oC-1] [3 marks] (d) Table 1.1 shows the heat of combustion of ethanol (C2H5OH), propanol (C3H7OH) and butanol (C4H9OH). Alcohol Molecular Formulae Heat of combustion/kJ mol-1 Ethanol C2H5OH 970 Propanol C3H7OH 1400 Butanol C4H9OH 1860 Table 1.1 For this experiment, state: (i) The manipulated variable................................................................................. The responding variable..................................................................................... The fixed variable............................................................................................... [3 marks] (ii) State one hypothesis for this experiment. .............................................................................................................................................................. .............................................................................................................................................................. ............................................................................................................................................................. [3 marks] (e) If the experiment is repeated using pentanol, predict the heat of combustion of pentane. ............................................................................................................................................................ [3 marks]. (f) State the operational definition for the heat of combustion of methanol. ............................................................................................................................................................ ............................................................................................................................................................ ........................................................................................................................................................... [3 marks] (g) The actual heat of combustion for ethanol is 1376 kJ mol-1. State three reasons why the experimental value heat of combustion for ethanol is less than the actual value. 1. ................................................................................................................................................ 2. ................................................................................................................................................ 3. ................................................................................................................................................ [3 marks] Chemistry Perfect Score Module 2011 63
  • 64. (h) Table 1.2 shows the list of carbon compounds and their molecular formula. Carbon compound Molecular formula Hexene C6H12 Propanoic acid C2H5COOH Ethanol C2H5OH Methane CH4 Classify the above carbon compounds into hydrocarbon and non hydrocarbon. [3 marks] 2. Diagram 2.1 and 2.2 show Experiment I and Experiment II to investigate the effect of type of electrodes on the products formed at the electrodes. Experiment I After 30 minutes Carbon electrodes Carbon electrodes Diagram 2.1 Experiment II After 30 minutes Copper electrodes 0.01 mol dm-3 copper(II) chloride solution Diagram 2.2 Based on Diagram 2.1 and Diagram 2.2 above, plan a laboratory experiment to investigate the effect of the type of electrode to the product at anode. Your answer should consist of the following: (a) Aim of experiment (b) All the variables (c) Hypothesis (d) List of materials and apparatus (e) Procedure (f) Tabulation of data [17 marks] END OF QUESTION PAPER Chemistry Perfect Score Module 2011 64