Standard Grade Revision Units 5 and 6 (a) A chemical which burns giving out energy. (b) Coal and natural gas. (c) Formed from dead sea animals. Remains buried under layers of rock for millions of years. Heat and pressure changed remains into oil. Q1. Crude oil is an example of a fossil fuel. (a) What is meant by the term ‘fuel’? (b) Name two other fossil fuels. (c) Describe how crude oil is formed. Q2. What are the tests for (a) Oxygen (b) Carbon dioxide. (c) Hydrogen. (a) Relights a glowing splint. (b) Turns lime water chalky (milky). (c) Burns with a ‘pop’ Standard Grade Chemistry

Units 5 and 6 Revision Q3. Which gas makes up (a) about 80% of the air? (b) about 20% of the air? Standard Grade Chemistry Q4. The fossil fuels are a finite resource. What is meant by the term ‘finite resource’? Q5. The word box gives the formulae of some oxides. H 2 O NO 2 K 2 O CaO COSO 2 (a) Identify the oxide produced by the sparking of air in car engines. (b) Identify the two oxides produced by burning hydrocarbons. (c) Identify the two oxides which are mainly responsible for acid rain. (a) Nitrogen. (b) Oxygen. A finite resource is a substance whose supply will run out in the future. (a) NO 2. (b) H 2 Oand CO. (c) NO 2 and SO 2.

Q6. The word box shows the formulae of some hydrocarbon compounds. CH 4 C 2 H 4 C 6 H 14 C 5 H 12 C 3 H 8 C 4 H 8 (a) Identify the molecular formula for pentane. (b) Identify the two molecular formulae which represent alkenes (c) Identify the hydrocarbon which has a boiling point of 69 o C. (You may want to use page 6 of the data booklet to help you). (d) Identify the two hydrocarbons formed when propane is cracked. Units 5 and 6 Revision Standard Grade Chemistry Q7. The word box shows the names of some hydrocarbons. cyclobutane cyclopentane butane propane ethane butene (a) Identify the hydrocarbon which is a liquid at 25 o C. (b) Identify the two isomers. (c) Identify the hydrocarbon that reacts quickly with bromine solution. (a) C 5 H 12 (b) C 2 H 4 and C 4 H 8 (c) C 6 H 14 (d) CH 4 and C 2 H 4. (a) Cyclopentane (b) Cyclobutane and butene (c) butene.

Units 5 and 6 Revision. Q8. Hexane can be cracked using aluminium oxide as the catalyst Standard Grade Chemistry One of the reactions taking place is C 6 H 14  C 2 H 4 + X (a) Draw the structural formula for hexane. (b) Write the molecular formula for X. (c) Name the product C 2 H 4. (d) Aluminium oxide is a white solid but at the end of the experiment it is covered with a black substance. Suggest what the black substance could be. Mineral wool soaked in hexane (a) (b) C 4 H 10 (c) Ethene (d) Carbon (soot)

Units 5 and 6 Revision. Q9. Dienes are a homologous series of hydrocarbons which contain two double bonds per molecule. Standard Grade Chemistry ( a) What is meant by the term “homologous series”? (b) Suggest a general formula for the dienes. (c) Write the molecular formula for the product of the complete reaction of penta-1,3-diene with bromine. (d) Draw the full structural formula for an isomer of buta-1,3-diene which contains only one double bond per molecule. (a)Family of compounds with same general formula. (b) C n H 2n-2. (c) C 5 H 8 Br 4. (d)

Q10. The diagram shows the names and boiling ranges of some of the fractions which are obtained from crude oil. Standard Grade Chemistry (a) Name the process which is used to separate the crude oil into fractions. (b) As shown in the diagram is (i) flammability increasing or decreasing? (ii) viscosity increasing or decreasing? (c) ) In which fraction is propane found? (Use your data booklet) (d) Decane is a compound found in the kerosene fraction. To which family of hydrocarbons does decane belong? (a) Fractional distillation. (b) (i) Increasing (ii) Decreasing. (c) Gases. (d) Alkanes.

Units 5 and 6 Revision. Q11. The alkanes are saturated hydrocarbons. The alkenes are unsaturated hydrocarbons. (a) What is meant by the term ‘saturated’? (b) What is meant by the term ‘unsaturated’? (c) What is the general formula of the (i) alkanes? (ii) alkenes? (d) Describe a chemical test that can be used to distinguish between alkanes and alkenes. Standard Grade Chemistry (a) Saturated means the compound contains only single C-C bonds. (b) Unsaturated means the compound contains a C=C double bond. (c) (i) Alkane general formula is C n H 2n+2. (ii) Alkenes general formula is C n H 2n. (d) Alkanes do not immediately decolourise bromine solution. Alkenes immediately decolourise bromine solution.

Units 5 and 6 Revision. Q12. Hydrocarbons are compounds which contain hydrogen and carbon only. Standard Grade Chemistry (a) Which box (A to E) shows the hydrocarbon which reacts with hydrogen to form butane. (b) Which two boxes show hydrocarbons which are isomers. (c) Which two boxes show hydrocarbons which are the first members of a homologous series (a) Box F (b) Boxes C and D (c) Boxes A and C

Units 5 and 6 Revision. Q13. Propene has the structural formula shown below. Standard Grade Chemistry Propene quickly decolourises bromine water, Br 2 (aq). (a) Name the type of chemical reaction which takes place when propene reacts with bromine water. (b)Draw the full structural formula for the product of the reaction. (c)Write a balanced equation for the complete combustion of propene. (a) Addition. (b) Br Br H H – C – C – C –H H H H (c) 2C 3 H 6 + 9O 2  6CO 2 + 6H 2 O

Standard Grade Chemistry Units 5 and 6 Revision. Q14. The burning of fossil fuels is a major source of air pollution. (a) Name the acidic gas formed when air in a car engine is sparked. (b) Name the acidic gas formed when coal with a high sulphur content is burned. (c) Name the toxic gas formed when methane is burned in a limited supply of air. (d) A catalytic converter fitted to a car exhaust reduces the amount of dangerous gases emitted into the atmosphere. Name the catalyst used in a catalytic converter. (a) Oxides of nitrogen such as nitrogen dioxide. (b) Sulphur dioxide. (c) Carbon monoxide. (d) Platinum.