science gcse core, additional and triple powerpoints

1. C6.13 Stages in chemical synthesis C6 Chemical synthesis Route map Over the next 12 lessons you will study : Friday 21 October 2011 C6.1 The chemical industry C6.2 Acids and alkalis C6.3 Reactions of acids C6.4 Salts from acids End of module test C6.5 Salts in our lives C6.6 Purity of chemicals C6.7 Rates of reactions C6.8 Factors affecting rates of reactions C6.9 Catalyst in industry C6.10 Chemical quantities C6.11 Stages in chemical synthesis C6.12 Measuring the yield

3. C6.7 Friday 21 October 2011 Introduction: The rate of any reaction tells us how quickly the product is formed over time. It also tells us whether a reaction proceeds slowly or violently. This is important, because chemists need to control reactions. If a reaction is too fast, it may cause an explosion. If it is to slow, it may make the process inefficient and therefore increase production costs. The rate of a reaction cannot be worked out directly from an equation. This only tells us the molecules that react and the molecules that are produced. There are several methods for determining the rate at which the reaction proceeds. These methods include: measuring the mass lost over time or a colour change over time or volume of gas produced over time. Rate of reaction= change in volume or mass t time Extension questions: 1: Why do we need to know the rate of a reaction ? 2: How can we measure the rate of a reaction ? 3: What are the factors that effect the rate of reaction ? 4: Look at the following reactions, from their equation suggest a method that would be appropriate to measure the rate of reaction. CaCO 3 (s) + 2HCl (l) CaCl 2 (aq) + CO 2 (g) + H 2 O (l) Mg (s) + 2HCl (s) MgCl 2 (aq) + H 2 (g) Know this: a: Know how to measure the rate of reaction by experimentation. b: Know that three factors can affect the rate of reaction, temperature, concentration and surface area.

4. Key concepts Look at the photograph and information and answer all the questions: Why is using a colorimeter better than using the human eye ? Explain why the mass lost method is far more accurate especially for studying initial rates when compared to the volume of gas ? The rate of a reaction cannot be worked out directly from an equation. This only tells us the molecules that react (substrates) and the molecules that are produced (products) You can determine the rate of reaction by actually performing the experiments in the laboratory. There are several methods for determining the rate at which the reaction proceeds. These methods include: C6.7 a Determining the rate of reaction by different methods

5. Key concepts Look at the photograph and information and answer all the questions: Explain the shape of the graph ? What would the graph look like if we use the volume of gas method (draw) ? In reactions involving the formation of a gas as a product, we can measure mass lost over time. As the gas is produced, it vents off into the atmosphere, reducing the total reaction mass. The electronic balance is able to monitor this loss of mass. Using this method, we can monitor the rate of reaction for a particular reaction. Plotting a graph allows us to work out the rate of reaction (grams of product per second) . C6.7 b Determining the rate of reaction using mass lost method Time (seconds) Mass lost (g)

6. Key concepts Look at the photograph and information and answer all the questions: What are the main problems with using the volume of gas method ? Explain the profile of the graph (above right) from start to finish ? In reactions involving the formation of a gas as a product, we can measure how quickly gas is produced over time. Using a conical flask and a syringe, the volume of gas produced over time can be recorded. Using this method we can monitor the rate of reaction for a particular reaction. Plotting a graph allows us to work out the rate of reaction (cm 3 of gas per second) Time (seconds) Gas volume (cm 3 ) C6.7 c Determining the rate of reaction using volume of gas

7. Key concepts Look at the photograph and information and answer all the questions: Explain why the data generated by the colorimeter is then fed to a computer ? Explain the profile of the graph (above right) from start to finish ? In reactions involving a change in colour when a substrate is used or a product is formed, we can measure the rate of reaction using a colorimeter. Using a small test tube called a vial, the reaction proceeds inside the colorimeter. Using this method we can monitor the rate of reaction for a particular reaction. Plotting a graph allows us to work out the rate of reaction (Absorbance of light) Time (seconds) Colour change (Abs) C6.7 d Determining the rate of reaction using a colorimeter Substrate A + B Colorimeter Products Data

8. C6.7 Plenary Lesson summary: collide molecules catalyst rate Friday 21 October 2011 How Science Works: Preparing for the next lesson: For atoms or _________ to react with one another and form new products during a chemical reaction, they have to ____with one another. How often and how hard they collide determines the overall ___ of reaction. Collisions of atoms or molecules involved in a chemical reaction are affected by temperature, concentration, size and a ______. Energy is needed to break the bonds in petrol (octane C 8 H 18 ) before new bonds can be formed by a reaction with oxygen. Once some of the bonds in one octane molecule have been broken the subsequent reaction with oxygen gives out enough energy to break the bonds in several other petrol molecules - and so on. Research into the factor that can affect the rate of reaction including temperature, concentration, surface area and the presence of a catalyst. Decide whether the following statements are true or false : False True 3: Increasing the temperature decreases the rate of reaction ? False True 2: If you increase the collision between reactant the rate of reaction increases ? False True 1: A formulae equation could tell us the rate of that reaction ?

10. Extension questions: 1: What are the factors that affect the rate of reaction ? 2: What happens to the rate of reaction if the concentration of either substrates is increased ? 3: Why doe milk kept at room temperature (25 o C) go sour more quickly than milk kept in a refrigerator (4 o C) ? 4: Explain a) why does cheese goes mouldy on the outside but not in the middle and b) why food can last forever when stored below freezing point ? Know this: a: Know that there are three main factors that effect the rate of reaction, temperature, concentration and particle size. b: Know that by increasing temperature only makes the reaction happened faster does not change the amount of final product. Friday 21 October 2011 Introduction: For atoms or molecules to react with one another and form new products during a chemical reaction, they have to collide with one another. How often and how hard they collide determines the overall rate of reaction . Collisions of atoms or molecules involved in a chemical reaction are affected by four main factors: 1: Temperature 2: Concentration 3: Particle size 4: Catalyst C6.8 Factors affecting the rate of reaction

11. Key concepts Look at the photograph and information and answer all the questions: In a reaction where manganese, copper and zinc metals were reacted with oxygen forming their oxide, the volume of oxygen (cm 3 ) used was recorded over time. A graph was plotted showing the reaction rates for the three metals. Look at the results, experimental set up and the graph and answer the questions ? Answer the following questions: 1: Which metal is the most reactive ? 2: For manganese, which part of the graph represents the fastest reaction rate ? 3: Which metal is the least reactive ? 4:When does the reaction between manganese and oxygen begin to slow down and why ? Heat source Oxygen Metal Oxygen is passed over the heated metal until the reaction has finished. C6.8 a A graph of volume of O 2 (cm 3 ) versus time (s) for the three metals was plotted. volume of oxygen (cm 3 ) Time (Seconds) Manganese oxide Copper oxide Zinc oxide A graph of volume of O 2 3 time (s) for the three metals was plotted. 3 ) Time (Seconds) Manganese oxide Copper oxide Zinc oxide (cm ) versus volume of oxygen (cm

12. Look at the photograph and information and answer all the questions: Give one example where a) heat or temperature b) concentration and c) particle size is used to speed up or slow down a chemical reaction ? Explain why powders are explosive and powders like magnesium or aluminium powder are dangerous if given to students in a laboratory ? Although collision theory is simple and states that for two or more substrates, they must first collide with sufficient energy to react and form new products, there are right and wrong collisions. During the combustion of methane with oxygen, not all collisions between the methane molecule and oxygen result in a successful reaction and the formation of new products (carbon dioxide and water.) Only one out of three collision as shown by the diagrams above have the correct orientation, so that the two substrates can react forming new products C6.8 b Key concepts Temperature Concentration Surface area

13. Key concepts Look at the photograph and information and answer all the questions: Explain a) in expt 1, only half the product is record when compare to the original and b) why in expt 2, the time taken for the reaction to finsh is less ? Look at the graph showing the effect of adding a catalysts to the reaction. Explain what happens to the rate of reaction ? The reaction between calcium carbonate (CaCO 3 ) and hydrochloric acid (HCl) which produces carbon dioxide gas was monitored over time using the volume of gas method. The amount of carbon dioxide produced over time was recorded. In expt. 1, the acid used was half the original concentration. In expt. 2, the temperature of the acid was increased by 10 o C to 30 o C. In expt. 3, a catalyst was used C6.8 c Factors affecting rate of reaction in action Carbon dioxide (CO 2 ) Calcium carbonate (CaCO 3 ) Hydrochloric acid (HCl) Volume of CO 2 (cm 3 ) 0 Time (seconds) Original 100 Expt. 1 Expt. 3 Expt. 2

14. 6.8 Plenary Lesson summary: harder chance faster concentration Friday 21 October 2011 Fireworks need to be explosive, so they use and are packed full of gun powder which rapidly releases energy. Keeping the powder in a small volume increases the concentration and the reaction happed very fast. How Science Works: Research into how catalysts increase the rate of reaction and ho the chemical industry can use catalysts to either increase the yield of a product or reduce the cost by reduce the operating tempeartures Preparing for the next lesson: As you increase the ________of a solution, there are more particles in the same volume of liquid, therefore there is a greater ___ that the particles will collide with each other to form new products. Reactions that are carried in higher temperature will make the particles to collide ______therefore the reaction will happened _____. Decide whether the following statements are true or false : False True 3: Sliced bread goes stale more quickly than un-sliced bread ? False True 2: You can increase the rate of reaction by making the reactant smaller in size ? False True 1: You can predict the rate of reaction for any reaction ?

16. Extension questions: 1: What is a catalyst ? 2: How does the catalyst effects the rate of a reaction ? 3:Give two examples of a catalyst ? 4: Why are catalyst important in the chemical industry ? 5: What happen to the catalyst itself in a chemical reaction ? 6: The human body has lots of biological catalysts, name what they are called and what role do they play ? Know this: a: Know that catalysts speed up the rate of reaction by lower the energy required to break bonds in the substrate molecules b: Know that catalysts are not used up in a reaction. they will not be shown in a word or symbol equation. Friday 21 October 2011 Introduction: A catalyst is a material which will increase the rate of reaction without be used up. Catalysts are normally transitional metals (Iron, Nickel & Platinum) which are able to lower the activation energy required for new products to form. The reaction takes place on the surface of the catalyst, known as the active site. Effective catalysts are normally in powdered form to help maximise the number of collisions between the reacting substrates and a catalyst’s active site. The bonds are broken and the substrates combine with on another to form new products, known as polythene. These new products then leave the active site, allowing the unchanged catalyst to participate in further reactions. Catalysts in industry C6.9

17. Key concepts Look at the photograph and information and answer all the questions: Why are catalysts not show in an overall equation that describe what substrates react with what to form new products ? Explain why scientists try a find catalyst that reduce a reaction’s a) temperature or b) pressure ? Catalysts speed up the rate of reaction by lowering the energy required to break bond present in the substrate molecules. Inorganic catalysts such as transition metals are used to catalyse a wide range of different reactions. Although catalysts are not permanently altered during the reactions that they catalyse, they can be poisoned by some impurities and will not work again. Diffusion of the reactant gases to the catalyst. Reactants adsorb to the surface of the catalyst. Bonds break of the adsorbed molecules. Making new bonds forming adsorbed product molecules. Product molecules leave the surface of the catalyst How catalysts work C6.9 a

18. Key concepts Look at the photograph and information and answer all the questions: Look at the first diagram. Its show energy distribution within substrates at 15 and 25 o C. Explain why the arte increases at the higher temperatures ? Look at the second diagram, its also shows the energy distribution with substrates. Explain why catalysts increase the arte of reaction ? In any reaction, there is a fixed number of substrate molecules able to collide and react to form a new product molecules. Their kinetic energy follows a typical normal distribution. Those substrate molecules with sufficient kinetic energy to collide, break existing bonds and therefore form new products account for only a small number of molecules within the whole population. How catalysts work C6.9 b Substrates with sufficient energy to form new products With catalyst Without catalysts Substrates with sufficient energy to form new products Temp 25 o C Temp 15 o C

19. C6.9 Plenary Lesson summary: collisions lower rate specific Friday 21 October 2011 The manufacture of ethanoic acid (which is used as a preservative) from methanol and carbon monoxide is only possible in the presence of a catalyst. Using Iridium metal as a catalyst decreases the required reaction temperature from 700 C to 200, and pressure from 700 to 30 atmospheres. The use of a catalysts saves a lot of energy and therefore cost . How Science Works: Find out how some of enzymes in our body work. Preparing for the next lesson: A catalyst will ____ the activation required for substrates to react with one another to form products. By adding a catalyst the activation energy decreases, increasing the number of successful ______and therefore increasing the _____of reaction. Enzymes are highly ______ for their substrate. Decide whether the following statements are true or false : False True 3: Increasing the temperature increases the rate of reaction ? False True 2: Temperature does not effect the rate of reaction ? False True 1: Catalyst are not used up in a reaction ?

21. C6.10 Extension questions: 1: What causes the break of the old bonds between atoms of reactant ? 2: Why decrease of temperature decreases the rate of a chemical reaction ? 3: what happened to the rate of a reaction if the concentration of the reactant are increased ? 4: What happened the amount of the product if a catalyst is used in a reaction ? Know this: a: Know that existing bonds have to begin breaking so that new ones can be formed . b: Know that collisions in which substrate molecules are moving with enough energy can break bonds and form new products. Friday 21 October 2011 Introduction: Chemical reactions involve the formation of bonds between atoms but often before new bonds can be formed old ones have to be broken. This means that there has to be enough energy (activation energy) to start breaking the old bonds before a reaction can occur. Increasing the temperature increases the energy of the molecules and lead to stronger and more often collision. Increasing the concentration and the surface area makes the collision more frequent. Using a catalyst changes the activation energy and control the amount of successful collisions in a reaction. Collision theory

22. Key concepts Look at the photograph and information and answer all the questions: Explain why an ignition spark or a heat source is required to kick start the reaction between methane and oxygen ? In order to determine the rate opf reaction between methane and water, would you measure the amount of carbon dioxide or water produced over time ? During a reaction, products are formed by substrates colliding into one another. Take methane which is rich in carbon and is a store of ancient chemical energy. During its combustion with oxygen, it releases its energy in the form of heat and light. The methane (CH 4 ) molecules breaks apart and forms new bonds with the oxygen atoms. The products of methane combustion with oxygen are water (H 2 O) and carbon dioxide. (C0 2 ) Substrates During the reaction Products C6.10 a C O O O O H H H C0 2 H 2 O H 2 O H O 2 O 2 CH 4

23. C6.10 b Look at the photograph and information and answer all the questions: Out of 1000 collisions for the reaction between methane and oxygen, how many would by on average successful ? Explain why it matters how substrates collide (think about what happens when substrates react and the bond that are broken) ? Although collision theory is simple and states that for two or more substrates, they must first collide with sufficient energy to react and form new products, there are right and wrong collisions. During the combustion of methane with oxygen, not all collisions between the methane molecule and oxygen result in a successful reaction and the formation of new products (carbon dioxide and water.) Only one out of three collision as shown by the diagrams above have the correct orientation, so that the two substrates can react forming new products Collision theory Key concepts

24. C6.10 Plenary Lesson summary: molecules collision bonds energy Friday 21 October 2011 The effect of changing conditions such as temperature or concentrations can be studied by measuring how long it takes to produce enough sulphur to make the solution opaque (non see-through) How Science Works: Research into chemical quantities and working out reacting masses and how much product will be formed. Preparing for the next lesson: When the molecules collide some _____between atoms are broken and new bond are formed. This creates new_____. There are millions of collisions every second. Only the ________where the molecules are moving with enough _____to break bonds between atoms are successful and lead to reaction. Decide whether the following statements are true or false : False True 3: Every molecule collision ends up with a reaction ? False True 2: For new products to form, substrates must collide and react with one another ? False True 1: If temperature increases substrates collide more often with greater energy ?

26. C6.11 Extension questions: 1: Look at the above equation if 46 grams of sodium forms 78 grams of sodium oxide, work out a) what 23 grams of sodium would form and b) 1 gram of sodium would form ? 2: Calculate the formula mass of H 2 O, NaOH and HCl, if H=1; O=16 and Na= 23 ? 3: Write a word and balanced symbol equation of the reaction between hydrochloric acid HCl and sodium hydroxide NaOH ? 4: Calculate the masses of reactant and the products of the above reaction ? Know this: a: Know that relative formula mass is sum of mass of all atoms in a formula. b: Know that to find the relative formula mass you just add up the relative atomic masses of the atoms in formula. Friday 21 October 2011 Introduction: To calculate the formula mass we simply add together the atomic masses of all the atoms shown in the formula. By using the formula masses in grams we can deduce what masses of reactants to use and what mass of products or the theoretical yield will be formed. The balanced symbol equation is used to work out the relative formula mass of each reactant and product. The relative reacting masses is times by the number used to balance the equation and add the units. Take the oxidation of sodium forming sodium oxide. Step one: write balanced equation: 2Na + O 2 2Na 2 O Step two: work out relative formula mass: 2 x 23 + 2 x 16 2 x 23 + 2 x 16 Step three: add in units for reacting masses: 46 g of Na + 32 g of O 2 78 g of Na 2 O Step four: scale quantities: 1kg of Na + 0.695kg of O 2 1.1695kg 0f Na 2 O Chemical quantities

27. Look at the photograph and information and answer all the questions: Once you understand the relative atomic mass of atoms, you can also work out the relative mass of any molecule or compound. Using its formula, all you have to do is add up the masses of each type of atom present in the molecule: e.g. The relative formula mass of carbon dioxide (CO 2 ) is 44 (CO 2 : 12 + 2 x 16 = 44 g) Work out the relative formula mass for the following compounds SO 2 , CO 2 & C 2 H 6 ? R.A.Ms: H = 1, C = 12, N= 14, O = 16, Ca = 20, Al = 27, S = 32? Methane Water Ethene Ammonia CH 4 H 2 O C 2 H 4 NH 3 12 + 4 x 1 = 16g 16 + 2 x 1 = 18g 2 x 12 + 4 x 1 = 28g 14 + 3 x 1 = 17g What would be the RFM of Mg(OH) 2 (magnesium hydroxide) be ? (RAM Mg = 24, O = 16 and H =2) Chlorine has a RAM of 35.5 What is the formula for magnesium chloride and what would its RFM be ? Understanding relative formula mass C6.11 a Key concepts 12 16 1 1 1 1 1 1 12 1 1 1 1 12 1 1 1 14

28. Look at the photograph and information and answer all the questions: The RFM of Fe 2 O 3 is 160. To get this you add together the RAM of each atom in the molecule. There are two iron atoms with a RAM of 56 and three oxygen atoms with a RAM of 16. Therefore 56 + 56 +16 + 16 +16 = 160 grams. Work out the relative formula mass for the following compounds SO 2 , CO 2 , C 2 H 6 & CO R.A.Ms: H = 1, C = 12, N= 14, O = 16, Ca = 20, Al = 27, S = 32 ? The formula of bauxite (aluminium oxide is Al 2 O 3 ) Work out its relative formula mass and what mass of aluminium would 100 kg of Al 2 O 3 yield ? Fe 2 O 3 Fe Fe O O O 56 56 16 16 16 56 + 56 16 +16 + 16 = 160g Once you understand the relative atomic mass of atoms, you can also work out the relative formula mass of any molecule or compound. Using its formula, all you have to do is add up the masses of each type of atom present in the molecule. For example ,the relative formula mass for a molecule of oxygen is twice 16 g, therefore 32 g (O 2 : 2 x 16 = 32 g) The formula of sodium chloride is NaCl. Work out a) the relative formula mass and b) the percentage by mass of Na in NaCl C6.11 b Understanding formulae Key concepts

29. Key concepts Look at the photograph and information and answer all the questions: Water is formed when hydrogen and oxygen collide and form new covalent bonds between the oxygen the hydrogen atoms: The balanced equation tells us that 16 grams of oxygen will react with 2 grams of hydrogen to form 18 grams of water. We can also use the equation to work out how much water would be formed if you reacted 1000 kg of oxygen in hydrogen. The mass of water formed would represent how many moles of water ? Is this yield the theoretical yield for the equation, percentage yield or the actual yield ? Write a balanced equation for the formation of water ? ½ O 2 + H 2 H 2 0 C6.11 c Understanding equations and reacting masses 16g O 2 2 g H 2 18 g H 2 0 1 g O 2 0. 125 g H 2 1. 125 g H 2 0 1 kg O 2 0. 125 kg H 2 1. 125 kg H 2 0 1000 kg O 2 125.0 kg H 2 1 125.0 kg H 2 0

30. C6.11 Plenary Lesson summary: theoretical reactants yield masses Friday 21 October 2011 Industrial processes use tonnes of reactants not grams. We can still use equation and formula masses to calculate masses of reactants and products. We simply swap grams for tonnes. How Science Works: Research into how chemists, scientists or industrial chemists take raw material to finished products. Think about how plastic (PET 1) used to make drinks bottle is made form ethylene to form the finished product. Preparing for the next lesson: The balanced equation for a reaction is used to work out the quantities of ________we need to use and calculate the ______ of products or the _______ yield. The actual _______is the mass of products after it is separated, purified and dried. Decide whether the following statements are true or false : False True 3: The actual yields is calculated using the formula mass of the products ? False True 2: The theoretical yield is equal with the actual yield ? False True 1: The mass of reactant is equal with the mass of reactant ?

33. Key concepts C6.12 a Look at the photograph and information and answer all the questions: Explain why old bottle are recycled in addition to using new PET 1 bulk materials ? Give three ways that we can encourage individuals and households to recycle more of their PT plastics ? Plastics are widely used in the foods and drinks industry. Polyethylene terephthalate or PET plastic has a resin code of 1. It is this type of PET plastic that is used to make drinks bottles. A new bottle can be made from PET made by polymerise ethylene molecules or by using recycled PET plastic that is sorted and shredded. This end product PET 1 is melted and then extruded into pellets which are then used to manufacture other products. Making plastics for drinksing bottles PET 1 plastic used to make PET drinking bottles

34. C6.12 b Look at the photograph and information and answer all the questions: The process Why do industrial chemists analyse each stage of an industrial process ? Explain the difference between a by-product and a waste material ? Raw materials Industrial process By-products Waste materials Can the amount of raw material be reduced to improve atom economy ? Can the process be made more energy efficient to reduce operating costs ? Is the yield as high as possible ? Questioning the process Can any of the by products be sold or reused ? Product yield Can the amount of waste material be reduce avoid landfill charges ? During the manufacture of any product (fine or bulk chemicals) chemists will work very hard to ensure that the synthesis process is as efficient as possible, that the product purity and quality is good and that the yield remains high. In an ideal chemical process the amount of starting materials or reactants equals the amount of all products generated and no atom is wasted. Recent developments like high raw material costs (such as petrochemicals) and increased sensitivity to environmental concerns have made the minimum use of raw materials and the production of waste important. Industrial chemical processes Key concepts

35. Key concepts C6.12 c Look at the photograph and information and answer all the questions: An industrial chemist will always consider and try and control the costs of every part of the industrial process from the cost of buying in raw materials to the cost of turning them into a new product. Chemists must also include the cost of disposing of waste chemicals and the cost of energy (heat and electricity) require during the manufacturing process. Yield % Product The price of the raw material begins to soar, how will this affect the cost of the finished product ? Explain why companies are now obliged to look at the ‘waste cost’ of their product ? Raw materials Material cost (£) Transport cost (£) Waste cost (£) Process cost (£) Electrical cost (£) Heating cost (£) Product cost (£) Transport cost (£) Waste cost (£) Synthesis pathway Reducing costs from raw materials to final product

36. C6.12 Plenary Lesson summary: risk exposure compounds equipment Friday 21 October 2011 Before any fine or bulk chemical is manufactured, research chemists test on a small scale the reaction, the raw material required, the final quality and yield of the product. Once all these parameters are maximised in the lab, the process is then scaled up to manufacture large quantities. How Science Works: Research into the manufacture and use of magnesium sulphate in micronutrients, soaps, additives to medicines and feed supplements Preparing for the next lesson: Chemical synthesis is a way of making new_______. It is a long process which involve a number of steps. A ____assessment is carried out before the reaction to identify hazardous chemicals, and hazard rising from the __________or procedures, in order to minimise _______ to risk. Decide whether the following statements are true or false : False True 3: It is rare to achieve 100% yields in any process ? False True 2: Using the correct amount of raw materials save costs ? False True 1: A risk assessment is carried out to identify reactant and products ?

39. Key concepts C6.13 a Look at the photograph and information and answer all the questions: What risks are associated when working with concentrated acids ? How would you separate a soluble salt like magnesium sulphate form its solution ? Magnesium carbonate (MgCO 3 ) and sulphuric acid (H 2 SO 4 ) is used to make magnesium sulphate (MgSO 4 ). It is made by taking powder magnesium carbonate and added to concentrated sulphuric acid. The reaction yield about 85% magnesium sulphate water and carbon dioxide. The magnesium sulphate is in solution and needs to be separated. substrates products Making magnesium sulphate MgSO 4 H 2 O H 2 SO 4 MgCO 3 H 2 SO 4 products MgCO 3

40. Look at the photograph and information and answer all the questions: Soaps containing magnesium sulphate is used to promote personal hygiene: Soap aids the removal of excess oil, dirt and dead skin, We consume in the UK much more soap that any other country making us one of the cleanest populations. It is important to note that magnesium sulphate helps to control the pH of the soap and also promotes the ‘froth’ formation. Soap quality is important to protect brand loyalty and also to make sure the consumer is unharmed by the product. How would you ensure the best quality soap ? Suggest why you would sample the raw materials and the finished product before it goes into bottles or packets and the product on the shelves ? A sample of your soap showed a high pH…what would you do ? (the soap has not yet been put into tubes) sample size and storage qualitative or quantitative analysis reliability of results sample homogenous or heterogeneous analysis of errors ? Analysis of soap... a case study C6.13 b Key concepts

42. C6.13 Plenary Lesson summary: quality raw filtered sulphuric Friday 21 October 2011 Ensuring a final product is ‘pure’ can sometimes be very expensive. Bulk chemicals tend to be between 95 and 98% pure. Fine chemicals tend to have a purity of over 99.9%. This make the production of fine chemicals much more expensive. How Science Works: Revise and prepare for an end of module test. Preparing for the next lesson: Chemical synthesis of magnesium sulphate require two _____ materials; magnesium carbonate and ________ acid. Once synthesis the magnesium sulphate is ________ and then further purified by evaporation and then crystallisation. Along each stage of the synthesis process ________ is always tested. Decide whether the following statements are true or false : False True 3: Filtering is a method used to measure the yield of the product ? False True 2: Evaporation is a method used to purify a soluble salt ? False True 1: A risk assessment is carried out when using strong acids ?