GCSE Additional Applied Science June 2008 Harnessing Chem Paper B

This document consists of 12 printed pages. SPA (SHW 00028 4/07) T45999/4 © OCR 2008 [T/103/3782] OCR is an exempt Charity [Turn over INSTRUCTIONS TO CANDIDATES • Write your name in capital letters, your Centre Number and Candidate Number in the boxes above. • Use blue or black ink. Pencil may be used for graphs and diagrams only. • Read each question carefully and make sure that you know what you have to do before starting your answer. • Answer all the questions. • Do not write in the bar codes. • Write your answer to each question in the space provided. INFORMATION FOR CANDIDATES • The number of marks for each question is given in brackets [ ] at the end of each question or part question. • The total number of marks for this paper is 36. * C U P /T 4 5 9 9 9 * FOR EXAMINER’S USE Qu. Max. Mark 1 10 2 4 3 9 4 13 TOTAL 36 GENERAL CERTIFICATE OF SECONDARY EDUCATION A335/02 TWENTY FIRST CENTURY SCIENCE ADDITIONAL APPLIED SCIENCE A Harnessing Chemicals (Higher Tier) WEDNESDAY 18 JUNE 2008 Afternoon Time: 45 minutes Candidates answer on the question paper. Additional materials (enclosed): None Calculators may be used. Additional materials: Pencil Ruler (cm/mm) H2 © OCR 2008 Answer all the questions. 1 Esters are chemicals with sweet, often fruity, smells. They are used to make the ink in scented pens. Brogan works as a technician for a manufacturer of scented inks. He follows a standard procedure to make the esters. The diagrams show the steps in the procedure. Step 1 • add 10 cm3 of alcohol to 10 cm3 of carboxylic acid in a distillation flask • add 2 cm3 of concentrated sulfuric acid to the flask • swirl the flask to mix • add the condenser and heat gently for 10 minutes3 [Turn over © OCR 2008 Step 2 • rearrange the equipment for distillation • heat the mixture up to 82 °C and collect the distillate (a) Sulfuric acid helps speed up the reaction and is not used up in the process. What is this type of chemical called? .......................................................... [1] (b) The distillate is poured into a beaker of sodium carbonate solution. This is to remove the sulfuric acid and any unreacted carboxylic acid. Name the gas released in this process. .......................................................... [1]4 © OCR 2008 (c) The ester found in an apple-scented pen is pentyl pentanoate. Pentyl pentanoate is made by reacting pentanol with pentanoic acid. Water is also made in this reaction. (i) Write the word equation for this reaction. + + [2] The formulae of the chemicals present in this reaction are shown below. A B C C H C C C H O H H H H H HH H H H C C C C C H H H H H H HH H H H C C H C C C OO H H H H H HH H C DH C C H H H C C C O O O H H H H HH H H (ii) What is the formula of the alcohol functional group? .......................................................... [1] (iii) What is the relative formula mass of D? You are advised to show how you work out your answer. (relative atomic masses: H=1, C=12, O=16) relative formula mass of D = ......................................................... [2]5 [Turn over © OCR 2008 (d) Esters are produced as fine chemicals using a batch process. (i) What is meant by the term fine? .......................................................................................................................................... .................................................................................................................................... [1] (ii) Explain one advantage and one disadvantage of a batch process. .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .................................................................................................................................... [2] [Total: 10]6 © OCR 2008 2 Most products we use in our homes are made from a mixture of ingredients. They are combined according to a fixed formula, called a formulation. The table below shows the different types of formulation, their description and examples. type of formulation description example emulsion an oily liquid dispersed in a watery liquid salad dressing solid mixture two or more ingredients mixed together solution a soluble solid dissolved in a liquid eye drops an insoluble solid dispersed in a liquid milk of magnesia (a) Complete the table. (i) Write the name of the missing formulation. [1] (ii) Give one example of a solid mixture. [1] (b) Why is an emulsifying agent added to an emulsion? .................................................................................................................................................. .................................................................................................................................................. ............................................................................................................................................ [2] [Total: 4]7 [Turn over © OCR 2008 3 An aqueous solution of potassium chloride is prepared using the following steps. The steps are in the wrong order. A Dissolve the potassium chloride in the smallest amount of water possible. B Rinse the beaker with water and add to the graduated flask. C Stopper the graduated flask and mix well. D Transfer the potassium chloride solution into a 100 cm3 graduated flask. E Accurately weigh 1.5 g of the solid potassium chloride and transfer into a beaker. F Add water drop by drop until the solution is up to the 100 cm3 mark. (a) Write down the correct order of the statements. The first one has been done for you. E .................. .................. .................. .................. .................. .................. [4] (b) It is important that the chemicals are transferred from one container to another with minimum loss. Describe two ways of transferring the potassium chloride solution to the graduated flask without spillage. .................................................................................................................................................. .................................................................................................................................................. ............................................................................................................................................ [2] (c) Name the solute used in this procedure. ............................................................................................................................................ [1]8 © OCR 2008 (d) 100 cm3 of the solution contains 1.5 g of potassium chloride. Calculate the concentration of the solution in grams per litre (g /l). You are advised to show how you work your answer out. concentration (g /l) = mass (g) volume (l) 100 cm3 = 100 ml concentration = ................................................... g /l [2] [Total: 9]9 [Turn over © OCR 2008 4 Nitrogen, N2 and hydrogen, H2 are used to make ammonia, NH3. (a) Write a balanced equation for this reaction. ............................................................................................................................................ [2] (b) Ammonia is made using a continuous process. nitrogen hydrogen nitrogen = ammonia = ammonia hydrogen = reactor unreacted nitrogen + hydrogen ammonia, nitrogen + hydrogen cooler (i) The hydrogen needed for this process is obtained from natural gas, from the North Sea. This method of obtaining hydrogen is not sustainable. Explain why. .......................................................................................................................................... .......................................................................................................................................... .................................................................................................................................... [2] (ii) Not all the nitrogen and hydrogen reacts to make ammonia in the reactor. What happens to the nitrogen and hydrogen which hasn’t reacted? .......................................................................................................................................... .................................................................................................................................... [1]10 © OCR 2008 (c) The graph below shows the amount of ammonia produced under different conditions. 0 100 200 300 400 0 10 20 30 40 50 60 70 80 pressure (atmospheres) % yield of ammonia 350 °C 450 °C 550 °C (i) Look at the graph. Which two conditions produce more ammonia? .......................................................................................................................................... .................................................................................................................................... [2] (ii) At 300 °C and a pressure of 100 atmospheres: percentage yield for ammonia is 40%; actual yield for ammonia is 5000 g. Calculate the theoretical yield for ammonia under these conditions. You are advised to show how you work out your answer. theoretical yield = actual yield percentage yield × 100 theoretical yield = ...................................................... g [2]11 © OCR 2008 (d) It is important to protect the health and safety of people who work in the chemical industry. Which organisation in the UK does this? ............................................................................................................................................ [1] (e) The ammonia produced has many uses. (i) A small amount of the ammonia produced is used to make nitric acid. What is the chemical formula of nitric acid? .......................................................... [1] (ii) Ammonia can be reacted with nitric acid to form the soluble salt ammonium nitrate which is used in fertilisers. The table shows the solubility of some common salts. soluble insoluble all nitrates most chlorides most sulfates sodium and potassium carbonate silver and lead chloride barium, lead and calcium sulfate most carbonates Put a ring around the two soluble salts in the list below. CaCO3 Pb(NO3)2 Na2CO3 MgCO3 CaSO4 [2] [Total: 13] END OF QUESTION PAPER12 © OCR 2008 PLEASE DO NOT WRITE ON THIS PAGE Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (OCR) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. OCR is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge.