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1

The diagram shows a Boltzmann distribution of molecular energies for a gaseous mixture. The distribution has a peak, labelled P on the diagram. activation energy P molecular energy number of molecules What happens when the temperature of the mixture increases?

8. Reaction kinetics  →  8.2. Effect of temperature on reaction rates and the concept of activation energy

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2

Substances X, Y and Z are all solids. Some of their physical properties are given in the table. substance X Y Z melting point / °C boiling point / °C electrical conductivity of the liquid state conducts does not conduct does not conduct What type of lattice could each substance have?

4. States of matter  →  4.2. Bonding and structure

9. The Periodic Table: chemical periodicity  →  9.1. Periodicity of physical properties of the elements in Period 3

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3

The enthalpy change of formation of carbon dioxide is –394 kJ mol–1. The enthalpy change of formation of water is –286 kJ mol–1. The enthalpy change of formation of methane is –74 kJ mol–1. What is the enthalpy change of combustion of methane?

5. Chemical energetics  →  5.1. Enthalpy change, \(\Delta H\)

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4

Hydrogen and carbon dioxide gases are mixed in equal molar amounts at 800 K. A reversible reaction takes place. H2+ CO2H2O+ COAt equilibrium, the partial pressures of H2 and CO2 are both 10.0 kPa. Kp is 0.288 at 800 K. What is the partial pressure of CO in the equilibrium mixture?

7. Equilibria  →  7.1. Chemical equilibria: reversible reactions, dynamic equilibrium

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5

In the diagram, curve X was obtained by observing the decomposition of 100 cm3 of 1.0 mol dm–3 hydrogen peroxide, catalysed by manganese(oxide. volume of oxygen formed 0 0 time Y X Which alteration to the original experimental conditions would produce curve Y?

5. Chemical energetics  →  5.1. Enthalpy change, \(\Delta H\)

2. Atoms, molecules and stoichiometry  →  2.4. Reacting masses and volumes (of solutions and gases)

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6

In which reaction is the species in bold acting as an oxidising agent?

6. Electrochemistry  →  6.1. Redox processes: electron transfer and changes in oxidation number (oxidation state)

13. An introduction to AS Level organic chemistry  →  13.2. Characteristic organic reactions

18. Carboxylic acids and derivatives  →  18.1. Carboxylic acids

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7

The formation of hydrogen and ethyne, C2H2, from methane reaches dynamic equilibrium. 2CH43H2+ C2H2What are the units of Kc?

7. Equilibria  →  7.1. Chemical equilibria: reversible reactions, dynamic equilibrium

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8

Which equation represents the standard enthalpy change of formation of ethanol, C2H5OH?

5. Chemical energetics  →  5.1. Enthalpy change, \(\Delta H\)

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9

Use of the Data Booklet is relevant to this question. In an experiment, 12.0 dm3 of oxygen, measured under room conditions, is used to burn completely 0.10 mol of propan-1-ol. What is the final volume of gas, measured under room conditions?

2. Atoms, molecules and stoichiometry  →  2.4. Reacting masses and volumes (of solutions and gases)

4. States of matter  →  4.1. The gaseous state: ideal and real gases and \( pV = nRT \)

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10

Shown...

1. Atomic structure  →  1.4. Ionisation energy

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11

The diagram shows the skeletal formula of cyclopropane. The enthalpy change of formation of cyclopropane is +53.3 kJ mol–1 and the enthalpy change of atomisation of graphite is +717 kJ mol–1. The bond enthalpy of H – H is 436 kJ mol–1 and of C – H is 410 kJ mol–1. What value for the average bond enthalpy of the C – C bond in cyclopropane can be calculated from this data?

5. Chemical energetics  →  5.1. Enthalpy change, \(\Delta H\)

5. Chemical energetics  →  5.2. Hess’s law

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12

When barium is burnt in oxygen, what colour is the flame?

10. Group 2  →  10.1. Similarities and trends in the properties of the Group 2 metals, magnesium to barium, and their compounds

11. Group 17  →  11.2. The chemical properties of the halogen elements and the hydrogen halides

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13

X and Y are oxides of different Period 3 elements. If one mole of Y is added to water, the solution formed is neutralised by exactly one mole of X. What could be the identities of X and Y?

9. The Periodic Table: chemical periodicity  →  9.2. Periodicity of chemical properties of the elements in Period 3

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14

Ammonium sulfate in the soil is slowly oxidised by air, producing sulfuric acid, nitric acid and water as the only products. How many moles of oxygen gas are needed for the complete oxidation of one mole of ammonium sulfate?

12. Nitrogen and sulfur  →  12.1. Nitrogen and sulfur

2. Atoms, molecules and stoichiometry  →  2.4. Reacting masses and volumes (of solutions and gases)

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15

Which statement about the oxides and hydroxides of the Group II elements Mg, Ca, Sr and Ba is correct?

10. Group 2  →  10.1. Similarities and trends in the properties of the Group 2 metals, magnesium to barium, and their compounds

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16

Which graph correctly shows the relative melting points of the elements Mg, Al, Si and P plotted against their relative electronegativities?

9. The Periodic Table: chemical periodicity  →  9.1. Periodicity of physical properties of the elements in Period 3

3. Chemical bonding  →  3.1. Electronegativity and bonding

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17

When solid sodium iodide reacts with concentrated sulfuric acid, the products include NaHSO4, H2S, SO2 and S. In the formation of which product has the oxidation state of sulfur changed by a value of 8?

12. Nitrogen and sulfur  →  12.1. Nitrogen and sulfur

11. Group 17  →  11.3. Some reactions of the halide ions

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18

A test-tube of HBrand a test-tube of HIare heated to the same temperature. Which combination of observations is possible?

5. Chemical energetics  →  5.1. Enthalpy change, \(\Delta H\)

8. Reaction kinetics  →  8.1. Rate of reaction

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19

Use of the Data Booklet is relevant to this question. In an experiment, 0.125 mol of chlorine gas, Cl 2, is reacted with an excess of cold aqueous sodium hydroxide. One of the products is a compound of sodium, oxygen, and chlorine. Which mass of this product is formed?

11. Group 17  →  11.4. The reactions of chlorine

2. Atoms, molecules and stoichiometry  →  2.4. Reacting masses and volumes (of solutions and gases)

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20

The diagram shows the skeletal formula of phenazine. N N phenazine N N What is the empirical formula of phenazine?

2. Atoms, molecules and stoichiometry  →  2.3. Formulas

13. An introduction to AS Level organic chemistry  →  13.1. Formulas, functional groups and the naming of organic compounds

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21

Halogenoalkanes undergo a range of nucleophilic substitution reactions. Which reaction proceeds only by an SN1 mechanism?

15. Halogen compounds  →  15.1. Halogenoalkanes

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22

Which alcohol has a chiral centre and can be oxidised to a ketone?

17. Carbonyl compounds  →  17.1. Aldehydes and ketones

16. Hydroxy compounds  →  16.1. Alcohols

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23

An ester of structural formula CH3CO2CH3 is heated with an aqueous solution of sodium hydroxide. What are the two organic products of this reaction?

15. Halogen compounds  →  15.1. Halogenoalkanes

18. Carboxylic acids and derivatives  →  18.2. Esters

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24

Ethene reacts with aqueous bromine to give two products, CH2BrCH2Br and CH2BrCH2OH. Which statement about these products is correct?

14. Hydrocarbons  →  14.2. Alkenes

15. Halogen compounds  →  15.1. Halogenoalkanes

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25

Which statement does not correctly describe a problem related to the disposal of PVC?

20. Polymerisation  →  20.1. Addition polymerisation

11. Group 17  →  11.4. The reactions of chlorine

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26

Compound X, C4H8O, produces an orange precipitate when it is reacted with 2,4-dinitrophenylhydrazine reagent. Compound X produces a carboxylic acid when heated under reflux with an acidified solution of potassium dichromate(. What could be compound X?

18. Carboxylic acids and derivatives  →  18.1. Carboxylic acids

17. Carbonyl compounds  →  17.1. Aldehydes and ketones

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27

Dichlorodifluoromethane, CCl 2F2, has been used in aerosol propellants and as a refrigerant. Which statement helps to explain why dichlorodifluoromethane is chemically inert?

11. Group 17  →  11.2. The chemical properties of the halogen elements and the hydrogen halides

11. Group 17  →  11.1. Physical properties of the Group 17 elements

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28

The diagram shows the structure of ethanedioic acid. HO C OH C O O Ethanedioic acid reacts with ethanol in the presence of a few drops of concentrated sulfuric acid to form a diester. The molecular formula of the diester is C6H10O4. What is the structural formula of the diester?

13. An introduction to AS Level organic chemistry  →  13.1. Formulas, functional groups and the naming of organic compounds

7. Equilibria  →  7.2. Brønsted–Lowry theory of acids and bases

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29

When heated with KOH dissolved in ethanol, halogenoalkanes can undergo an elimination reaction to form alkenes. What are the possible elimination products when 2-bromobutane is heated with KOH dissolved in ethanol?

15. Halogen compounds  →  15.1. Halogenoalkanes

14. Hydrocarbons  →  14.2. Alkenes

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30

Artemisinin is a powerful anti-malarial drug. O O O O O CH3 CH3 CH3 artemisinin How many chiral centres are there in each molecule of artemisinin?

13. An introduction to AS Level organic chemistry  →  13.4. Isomerism: structural isomerism and stereoisomerism

13. An introduction to AS Level organic chemistry  →  13.1. Formulas, functional groups and the naming of organic compounds

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31

P and Q are two compounds with similar Mr values. Molecules of P attract each other by hydrogen bonds. Molecules of Q attract each other by van der Waals’ forces only. A sample of liquid P is compared to a sample of liquid Q. How will their properties differ?

3. Chemical bonding  →  3.6. Intermolecular forces, electronegativity and bond properties

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32

The reaction E + F G + H is catalysed by platinum. Which statements about the properties of the catalyst are correct?

8. Reaction kinetics  →  8.3. Homogeneous and heterogeneous catalysts

5. Chemical energetics  →  5.1. Enthalpy change, \(\Delta H\)

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33

Which elements have atoms which can form π bonds with atoms of other elements?

3. Chemical bonding  →  3.4. Covalent bonding and coordinate (dative covalent) bonding

13. An introduction to AS Level organic chemistry  →  13.3. Shapes of organic molecules; σ and π bonds

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34

Sulfuric acid is a Brønsted-Lowry acid. In which reactions is sulfuric acid behaving as an acid?

7. Equilibria  →  7.2. Brønsted–Lowry theory of acids and bases

18. Carboxylic acids and derivatives  →  18.1. Carboxylic acids

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35

Silver chloride dissolves in aqueous ammonia. What happens in this process?

11. Group 17  →  11.3. Some reactions of the halide ions

15. Halogen compounds  →  15.1. Halogenoalkanes

12. Nitrogen and sulfur  →  12.1. Nitrogen and sulfur

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36

A car has a catalytic converter fitted to its exhaust. On analysis its exhaust gases are shown...

12. Nitrogen and sulfur  →  12.1. Nitrogen and sulfur

14. Hydrocarbons  →  14.1. Alkanes

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37

Which alcohols cannot be dehydrated to form alkenes?

16. Hydroxy compounds  →  16.1. Alcohols

14. Hydrocarbons  →  14.2. Alkenes

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38

Menthol is a naturally-occurring alcohol found in peppermint oil. OH menthol Which reagents will react with menthol?

16. Hydroxy compounds  →  16.1. Alcohols

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39

Which pairs of reagents will take part in a redox reaction under suitable conditions?

17. Carbonyl compounds  →  17.1. Aldehydes and ketones

13. An introduction to AS Level organic chemistry  →  13.2. Characteristic organic reactions

18. Carboxylic acids and derivatives  →  18.1. Carboxylic acids

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40

Propanoic acid occurs naturally as a result of the bacterial fermentation of milk, and is partly responsible for the flavour of Swiss cheese. propanoic acid OH O Which starting materials could be used to synthesise propanoic acid?

18. Carboxylic acids and derivatives  →  18.1. Carboxylic acids

7. Equilibria  →  7.2. Brønsted–Lowry theory of acids and bases

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