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11. Organic chemistry
A section of Chemistry, 0620
Listing 10 of 1367 questions
The names of nine substances are shown. aluminium oxide ammonia carbon monoxide anhydrous cobalt(chloride hydrated copper(sulfate iron(oxide nitrogen dioxide silver steel Answer the following questions using these substances. Each substance may be used once, more than once or not at all. Name the substance that is: the main constituent of hematite ������������������������������������������������������������������������������������������ a gas produced in car engines which causes acid rain ������������������������������������������������������� an alkaline gas ��������������������������������������������������������������������������������������������������������������������� an element ��������������������������������������������������������������������������������������������������������������������������� a gas formed by the incomplete combustion of fossil fuels ������������������������������������������������� used to test for the presence of water. �������������������������������������������������������������������������������� 
0620_w20_qp_43
THEORY
2020
Paper 4, Variant 3
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The diagram shows the structures of some substances containing carbon. A B C D E F O C O H C H H H H C H Ca2+ CO3 2– CO3 2– CO3 2– CO3 2– CO3 2– CO3 2– CO3 2– CO3 2– Ca2+ Ca2+ Ca2+ Ca2+ Ca2+ Ca2+ Ca2+ C Cl Cl Cl Cl C C H H H C H H H Answer the following questions about these substances. Each substance may be used once, more than once or not at all. Which substance, A, B, C, D, E or F is a saturated hydrocarbon, has an ionic structure, is a product of respiration, is in the same homologous series as methane, is used for cutting? Substance D is an element. Explain why substance D is an element.
0620_m15_qp_22
THEORY
2015
Paper 2, Variant 2
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Alcohols are a ‘family’ of organic molecules which have the same general formula. What is the name given to any ‘family’ of organic molecules which have the same general formula and similar chemical properties? Give the general formula of alcohols. Propan-1-ol can be made from propene. Name the reagent and give the conditions needed to convert propene into propan-1-ol. reagent conditions  Write a chemical equation for the complete combustion of propan-1-ol. A simple sugar can be represented as shown. O O H H Simple sugars can be polymerised to make more complex carbohydrates. Complete the diagram to show part of a carbohydrate polymer made from the simple sugar shown.  Name the chemical process which occurs when a carbohydrate polymer is broken down into simple sugars. What conditions are needed for this process to occur? Chromatography can be used to identify simple sugars in a mixture. A student analysed a mixture of simple sugars by chromatography. All the simple sugars in the mixture were colourless. What is the name given to the type of substance used to identify the positions of the simple sugars on the chromatogram? The student calculated the Rf value of a spot on the chromatogram. Complete the expression for the Rf value of the spot. Rf =  How could a student identify a simple sugar from its Rf value? Sometimes not all the substances in a mixture can be identified from the chromatogram produced. Explain why this may happen. 
0620_m18_qp_42
THEORY
2018
Paper 4, Variant 2
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For Examiner's Use Esters, fats and polyesters all contain the ester linkage. The structural formula of an ester is given below. C H H H H C C O O H H H H C H H H H C C Name two chemicals that could be used to make this ester and draw their structural formulae. Show all bonds. names and structural formulae Draw the structural formula of a polyester such as Terylene. Suggest a use for this polymer. For Examiner's Use Cooking products, fats and vegetable oils, are mixtures of saturated and unsaturated esters. The degree of unsaturation can be estimated by the following experiment. 4 drops of the oil are dissolved in 5 cm3 of ethanol. Dilute bromine water is added a drop at a time until the brown colour no longer disappears. Enough bromine has been added to the sample to react with all the double bonds. cooking product mass of saturated fat in 100 g of product / g mass of unsaturated fat in 100 g of product / g number of drops of bromine water margarine butter corn oil soya oil lard Complete the one blank space in the table. Complete the equation for bromine reacting with a double bond. C C + Br2 Using saturated fats in the diet is thought to be a major cause of heart disease. Which of the products is the least likely to cause heart disease? For Examiner's Use A better way of measuring the degree of unsaturation is to find the iodine number of the unsaturated compound. This is the mass of iodine that reacts with all the double bonds in 100 g of the fat. Use the following information to calculate the number of double bonds in one molecule of the fat. Mass of one mole of the fat is 884 g. One mole of I2 reacts with one mole C C . The iodine number of the fat is 86.2 g. Complete the following calculation. 100 g of fat reacts with 86.2 g of iodine. 884 g of fat reacts with g of iodine. One mole of fat reacts with moles of iodine molecules. Number of double bonds in one molecule of fat is
0620_s07_qp_3
THEORY
2007
Paper 3, Variant 0
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