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1

The diagram shows the Boltzmann distribution of energies in a gas. The gas undergoes a reaction with an activation energy, Ea. The peak of the distribution is labelled P. Ea molecular energy, E proportion of molecules with energy E P If the same reaction is carried out in the presence of a catalyst, which statement is correct?

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

8. Reaction kinetics  →  8.3. Homogeneous and heterogeneous catalysts

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2

Diamond is a pure form of carbon. The mass of a diamond can be measured in carats. One carat is 0.200 g of carbon. Which expression gives the number of carats that contain 6.02 × 1023 carbon atoms?

22. Analytical techniques  →  22.2. Mass spectrometry

2. Atoms, molecules and stoichiometry  →  2.1. Relative masses of atoms and molecules

1. Atomic structure  →  1.1. Particles in the atom and atomic radius

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3

Which molecule or ion contains the smallest bond angle?

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

3. Chemical bonding  →  3.5. Shapes of molecules

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4

Four compounds are shown...

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

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

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5

Ethanal, CH3CHO, ethanol, C2H5OH, and methoxymethane, CH3OCH3, are three organic compounds. Which compound has the highest boiling point and what is the interaction that causes this boiling point to be the highest?

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

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

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6

What is the oxidation number of sulfur in each species?

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

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7

The following data are needed for this question. (N2H4) = 50.6 kJ mol–1 (N2O4) = 9.2 kJ mol–1 (H2O) = –241.8 kJ mol–1 Hydrazine, N2H4, reacts with dinitrogen tetraoxide, N2O4, to form nitrogen gas and water vapour. 2N2H4+ N2O4→ 3N2+ 4H2OWhat is the enthalpy change for this reaction?

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

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8

Sodium burns in oxygen giving out heat energy and forming the compound Na2O. The equation for this reaction is shown...

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

11. Group 17  →  11.4. The reactions of chlorine

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9

In the chemical equation, w, x, y and z are all whole numbers. wCl O3 – + xMnO4 – + yH+ → wCl O4 – + xMnO2 + zH2O When the equation is balanced, what are w, x and y?

11. Group 17  →  11.4. The reactions of chlorine

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

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10

Two compounds X and Y react to produce compound Z. The reaction is reversible. X + Y Z When X and Y are mixed together in a closed system a dynamic equilibrium is gradually established. Which graph could represent the change in the rates of the forward and reverse reactions over time?

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

8. Reaction kinetics  →  8.1. Rate of reaction

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11

The reaction between sulfur dioxide and oxygen is reversible. 2SO2+ O22SO3Kc = 280 mol–1 dm3 at 1000 K In an equilibrium mixture at 1000 K the sulfur dioxide concentration is 0.200 mol dm–3 and the oxygen concentration is 0.100 mol dm–3. What is the sulfur trioxide concentration?

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

12. Nitrogen and sulfur  →  12.1. Nitrogen and sulfur

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12

Which oxide will cause an increase in pH when added to water?

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

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

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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13

X, Y and Z are consecutive elements in Period 3 of the Periodic Table. Element Y has the highest first ionisation energy and the lowest melting point of these three elements. What are the identities of X, Y and Z?

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

1. Atomic structure  →  1.4. Ionisation energy

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14

A 5.00 g sample of an anhydrous Group 2 metal nitrate loses 3.29 g in mass when heated strongly. Which metal is present?

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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15

Solutions P and Q each contain a different Group 2 ion at the same concentration. One contains Mg2+, the other contains Ba2+. Tests are carried out on separate 5 cm3 samples of P and Q. test 1: add 1 cm3 of 0.1 mol dm–3 Na2SO4test 2: add 1 cm3 of 0.1 mol dm–3 NaOHWhat are the results of these tests?

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

16. Hydroxy compounds  →  16.1. Alcohols

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

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16

Chlorine and bromine have different volatilities. Which row identifies the more volatile of the two elements, and gives the correct explanation?

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

22. Analytical techniques  →  22.2. Mass spectrometry

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17

Sodium azide, NaN3, is dissolved in water. Acidified silver nitrate is added to the solution and a white precipitate forms. Aqueous ammonia is then added to the white precipitate. The azide ion, N3 –, has similar chemical properties to the Cl – ion. Which row of the table can be predicted from this information?

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

2. Atoms, molecules and stoichiometry  →  2.3. Formulas

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18

Which type of reaction occurs when solid ammonium sulfate is heated with an excess of sodium hydroxide solution?

12. Nitrogen and sulfur  →  12.1. Nitrogen and sulfur

11. Group 17  →  11.4. The reactions of chlorine

18. Carboxylic acids and derivatives  →  18.2. Esters

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19

Catalytic converters are fitted in the exhaust systems of many cars. Which gas: ● causes acid rain if it is released into the air ● is removed from car exhaust fumes by a catalytic converter?

12. Nitrogen and sulfur  →  12.1. Nitrogen and sulfur

14. Hydrocarbons  →  14.1. Alkanes

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20

Which substance reacts with trichloroethene to give a chiral product?

15. Halogen compounds  →  15.1. Halogenoalkanes

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21

Alkanes are saturated hydrocarbons. Which type of reaction are alkanes most likely to undergo?

14. Hydrocarbons  →  14.1. Alkanes

14. Hydrocarbons  →  14.2. Alkenes

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22

An alkene reacts with hot, concentrated, acidified potassium manganate(to produce a single organic product as shown...

14. Hydrocarbons  →  14.2. Alkenes

17. Carbonyl compounds  →  17.1. Aldehydes and ketones

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23

A tertiary bromoalkane, indicated here by C–Br, reacts with aqueous NaOH. The mechanism has the reaction pathway shown...

15. Halogen compounds  →  15.1. Halogenoalkanes

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

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24

Bromoethane and chloroethane are added separately to water. Hydrolysis reactions occur. Which compound hydrolyses more rapidly and what is the mechanism?

15. Halogen compounds  →  15.1. Halogenoalkanes

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25

Alcohol X is oxidised to form compound Y. The composition of Y is 54.54% carbon, 36.36% oxygen and 9.10% hydrogen. The Mr of Y is 88.0. What could be the structure of alcohol X?

16. Hydroxy compounds  →  16.1. Alcohols

4. States of matter  →  4.2. Bonding and structure

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26

The diagram shows the structure of compound Z. Z O O What is the product of the reaction between compound Z and an excess of NaBH4?

16. Hydroxy compounds  →  16.1. Alcohols

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

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

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27

Compound Q shows the following reactions. ● It gives an orange precipitate with 2,4-dinitrophenylhydrazine. ● It gives a red-brown precipitate with Fehling’s reagent. ● It gives a pale yellow precipitate with alkaline aqueous iodine. What could be the identity of Q?

17. Carbonyl compounds  →  17.1. Aldehydes and ketones

16. Hydroxy compounds  →  16.1. Alcohols

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28

Tartaric acid, HO2CCH(OH)CH(OH)CO2H, is found in many plants. A sample of tartaric acid reacts with an excess of LiAl H4 to form the organic product J. What happens when NaOHis added to separate samples of tartaric acid and J?

18. Carboxylic acids and derivatives  →  18.1. Carboxylic acids

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

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29

When CH2(OH)CH=CHCO2H is warmed with a little concentrated sulfuric acid, a cyclic compound is formed. What is the skeletal formula of the cyclic compound?

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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30

The infra-red spectrum of compound P is shown...

22. Analytical techniques  →  22.2. Mass spectrometry

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

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31

A particular atom of germanium, Ge, has a nucleon number of 70. Which statements about a Ge atom are correct?

1. Atomic structure  →  1.1. Particles in the atom and atomic radius

1. Atomic structure  →  1.3. Electrons, energy levels and atomic orbitals

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32

The first ionisation energy of chlorine is greater than that of sulfur. Which factors contribute to this?

1. Atomic structure  →  1.4. Ionisation energy

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33

Liquids X and Y do not react with one another. They have identical boiling points. When a particular volume of X is shaken with a similar volume of Y, they form a liquid mixture Z. The average intermolecular forces in liquid Z are stronger than the average of the forces in X and the forces in Y. Which deductions from this information are correct?

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

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

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34

The stoichiometry of a catalysed reaction is shown...

8. Reaction kinetics  →  8.1. Rate of reaction

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

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35

Which statements are correct?

11. Group 17  →  11.4. The reactions of chlorine

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

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36

Nitrogen gas is unreactive, whereas oxygen gas and chlorine gas are reactive. Which statements help to explain this difference?

12. Nitrogen and sulfur  →  12.1. Nitrogen and sulfur

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

14. Hydrocarbons  →  14.1. Alkanes

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37

The structure of tiglic acid is CH3CH=C(CH3)CO2H. Which statements about the properties of one molecule of this acid are correct?

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

4. States of matter  →  4.2. Bonding and structure

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38

Which compounds, on heating with an excess of concentrated sulfuric acid, produce only one product with molecular formula C7H10?

16. Hydroxy compounds  →  16.1. Alcohols

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

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

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39

Hydrogen cyanide reacts with propanone in the presence of potassium cyanide. Which statements about this reaction are correct?

17. Carbonyl compounds  →  17.1. Aldehydes and ketones

19. Nitrogen compounds  →  19.2. Nitriles and hydroxynitriles

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40

Which compounds produce three different organic products when hydrolysed?

21. Organic synthesis  →  21.1. Organic synthesis

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

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