Chemistry paper 2


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Chemistry paper 2

  1. 1. SULIT 4541/21Section A[60 marks]Answer all questions.1. Table shows the numbers of protons and neutrons for atoms W, X, Y and Z.Atom Number of protons Number of neutronsW 8 9X 8 10Y 12 12Z 11 12(a) (i) What is meant by nucleon number?________________________________________________________________________[1 mark](ii) What is the nucleon number of atom W?________________________________________________________________________[1 mark](b) Write the symbol of atom Y in the form of z Y.___________________________________________________________________________[1 mark](c) (i) Write the electron arrangement of atom Z.________________________________________________________________________[1 mark](ii)What is the number of valence electrons in atom Z?________________________________________________________________________[1 mark](d) Which atoms are isotopes? Explain why._____________________________________________________________________________________________________________________________________________________[2 marks]A
  2. 2. SULIT 4541/22(e) Solid Q is a compound of element W. Solid Q has melting point of 85C and boiling point of150C. A boiling tube containing solid Q is heated at room temperature until 180C.(i) Sketch a graph of temperature against time during heating.[2 marks](ii) Draw the arrangement of particles of substance Q at 50C.[1 mark]2. Diagram shows the set-up of apparatus to investigate the electrolysis of silver nitrate solutionwith carbon electrodes and copper(II) sulphate solution with copper electrodes.(a) What is the energy change in electrolysis?__________________________________________________________________________[1 mark]
  3. 3. SULIT 4541/23(b) Write the formulae of all the ions present in silver nitrate solution.__________________________________________________________________________[1 mark](c) In the electrolysis of Cell 1(i) What is the observation at electrode B?_________________________________________________________________[1 mark](ii) Write the half equation for the reaction at electrode B._________________________________________________________________[1 mark](d) In the electrolysis of Cell 2(i) What is the observation at electrode C?_________________________________________________________________[1 mark](ii) Write the half equation for the reaction at electrode C._________________________________________________________________[1 mark](e) What are the processes that occur at electrodes A and D?Electrode A: __________________________________________________________Electrode B: __________________________________________________________[2 marks](f) State which cell the concentration of electrolyte remains unchanged.___________________________________________________________________________[1 mark](g) State one application of electrolysis in industrial.___________________________________________________________________________[1 mark]
  4. 4. SULIT 4541/243. Diagram shows a series of reactions of lead(II) carbonate.(a) (i) Name the solid P.________________________________________________________________________[1 mark](ii) Draw a labeled diagram of the set-up of apparatus can be used to produce solid P and toidentify gas Q in step I.[2 marks](iii) Write the chemical equation for the decomposition of lead(II) carbonate whenheated._________________________________________________________________[1 mark]
  5. 5. SULIT 4541/25(iv) 13.35 g of lead(II) carbonate is heated to decompose completely, calculate thevolume of gas Q produced at room conditions.[Relative atomic mass: Pb = 207, C = 12, O = 16, and 1 mol of gas occupies 24dm3at room conditions][2 marks](b) (i) Name the precipitate X.________________________________________________________________________[1 mark](ii) State the colour of precipitate X._______________________________________________________________________[1 mark](iii)Write the ionic equation for the formation of precipitate X._______________________________________________________________________[1 mark](iv) How to obtain precipitate X from the mixture?_______________________________________________________________________[1 mark]
  6. 6. SULIT 4541/264. Two experiments were carried out to investigate factors that affect the rate of reaction. Tableshows the description of each experiment.Experiment Reactants Temperature/CTotal volume of gascollected at 2minutes/cm3IExcess zinc powder + 20 cm3of 0.1 mol dm-3sulphuric acid30 20.0IIExcess zinc powder + 20 cm3of 0.1 mol dm-3sulphuric acid+ copper(II) sulphate solution30 32.0(a) Draw a diagram of the set-up of apparatus to carry out this experiment.[2 marks](b) Write the chemical equation for the reaction between zinc and sulphuric acid.__________________________________________________________________________[1 mark](c) Calculate the average rate of the reaction for the first two minutes of experiment I andexperiment II in cm3s-1.Experiment I:Experiment II:[2 marks]
  7. 7. SULIT 4541/27(d) Calculate the maximum volume of gas produced in experiment II.[1 mol of gas occupies 24 dm3at room conditions][2 marks](e) Compare the rate of reaction between experiment I and II, explain why there is a difference inthe rate of reaction based on the collision theory._________________________________________________________________________________________________________________________________________________________________________________________________________________________________[3 marks]5. Table shows molecular formulae of 4 carbon compounds.Compound Molecular formulaA C4H8B C4H10C C4H9OHD C2H5COOH(a) Write the general formula of the homologous series of compound B.___________________________________________________________________________[1 mark](b) State the functional group of compound A and compound D.Compound A: __________________________________________________________Compound D: __________________________________________________________[2 marks]
  8. 8. SULIT 4541/28(c) Compound B shows isomerism. Draw the structural formula of all isomers of compound B.[2 marks](d) Compound D and compound C are reacted with the presence of the concentrated sulphuricacid.(i) Name the product formed from the reaction.________________________________________________________________________[1 mark](ii) State one special characteristic of the product formed.________________________________________________________________________[1mark](e) Compound A burns in excess oxygen to produce carbon dioxide and water.(i) Write a balanced chemical equation for the reaction.________________________________________________________________________[1 mark](ii) 11.2 g of compound A burns in excess oxygen, calculate the number of carbon dioxidemolecules formed.[Relative atomic mass C = 12, O = 16 and Avogadro number = 6.02 x 1023][2 marks]
  9. 9. SULIT 4541/296. Diagram shows the apparatus set-up to determine the empirical formula of oxide metal M.(a) (i) State the name of two reactants to prepare hydrogen gas in the laboratory.________________________________________________________________________[1 mark](ii) Write the chemical equation for the reaction in (a)(i).________________________________________________________________________[1 mark](b) State one precaution that must be taken when carrying out the experiment.___________________________________________________________________________[1 mark](c) Table shows the results of the experiment.Mass of combustion tube + asbestos paper 36.50 gMass of combustion tube + asbestos paper + M oxide 37.30 gMass of combustion tube + asbestos paper + M 37.14 g(i) Based on the results, determine the empirical formula of M oxide.[Relative atomic mass: O = 16, M = 64][3 marks]
  10. 10. SULIT 4541/210(ii) Write the chemical equation for the reaction between M oxide and hydrogen gas.________________________________________________________________________[1 mark](d) (i) The empirical formula of magnesium oxide cannot be determined by the above method.Explain why.________________________________________________________________________[1 mark](ii) Draw a suitable set-up of apparatus for the experiment to determine the empirical formulaof magnesium oxide.[2 marks]
  11. 11. SULIT 4541/211Section B[20 marks]Answer any one question from this section7. (a) Element X reacts with element Y to form a compound. Diagram shows the electronarrangement of the compound.(i) Write the electron arrangement of atom of element X. State the position ofelement X in the Periodic Table of Elements.[3 marks](iii) Write the chemical equation for the reaction between element X and element Y.Explain how the bond in the compound formed.[7 marks](b) Diagram shows the set-up of apparatus to investigate the electrical conductivity oflead(II) bromide and naphthalene.Table shows the result obtained.Substance State of substance ObservationLead(II) bromideSolid The bulb does not glowMolten The bulb glows brightlyNaphthaleneSolid The bulb does not glowMolten The bulb does not glowExplain the observation in the table above.Write the chemical equation for the reaction at cathode and anode.[10 marks]
  12. 12. SULIT 4541/2128. Diagram shows the flow chart for the reactions of propan-1-ol.(a) Draw the structural formula and state the name of compounds X, Y and Z.[6 marks](b) State the type of Reaction I and explain a chemical test to identify compound X.[3 marks](c) Compound X can be converted into propan-1-ol. Write the chemical equation and state theconditions needed for the reaction.[3 marks](d) In Reaction III, describe the method of preparing compound Z in laboratory.[4 marks](e) When calcium carbonate is added to compound Y, carbon dioxide gas is liberated. State the name of the functional group of compound Y Write the general formula of compound Y Write the chemical equation of the reaction[4 marks]
  13. 13. SULIT 4541/213Section C[20 marks]Answer any one question from this section9. (a) (i) What is a catalyst?(ii) State two characteristics of a catalyst.(iii) Name one chemical process and the catalyst used in industry.[4 marks](b) State two factors other than catalyst which can affect the rate of reaction. Based on thecollision theory, explain how the factors that you mentioned can affect the rate ofreaction.[8 marks](c) Knowledge about the factors that affect the rate of reaction is very useful in human life.State two activities at home and explain how the knowledge about the factors that affectthe rate of reaction is applied in the activities mentioned.[8 marks]10. (a) Table shows the potential difference and the negative terminal when different pairs ofmetals are used in a simple voltaic cell to construct electrochemical series.Pair of metals Potential difference/V Negative terminalQ – R 0.2 QR – S 0.8 RP – S 2.6 PP – Q x y(i) By using a simple voltaic cell, describe an experiment to determine the position ofmetals P, Q, R and S in electrochemical series.[10 marks](ii) Based on data in the table above, predict the x value of the potential difference of pair ofmetals P – Q and the negative terminal, y.If metal Q is zinc, suggest the identity of metal P. Explain your answer.[4 marks]
  14. 14. SULIT 4541/214(b) Table shows the observations at the anode when two different electrolytes areelectrolysed using carbon electrodes.Electrolyte Observation at anode1.0 mol dm-3sodium chloride A yellowish gas is released0.0001 mol dm-3sodium chloride A colourless gas is releasedBased on the information in the table, explain the observations at the anode for bothelectrolytes.[6 marks]END OF QUESTION PAPER