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1

Which formula represents the empirical formula of a compound?

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

2. Atoms, molecules and stoichiometry  →  2.3. Formulas

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2

The relative first ionisation energies of four elements with consecutive atomic numbers below 20 are shown...

1. Atomic structure  →  1.4. Ionisation energy

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3

In which structure are three atoms bonded together in a straight line?

4. States of matter  →  4.2. Bonding and structure

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

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4

In the sodium chloride lattice the number of chloride ions that surround each sodium ion is called the co-ordination number of the sodium ions. What are the co-ordination numbers of the sodium ions and the chloride ions in the sodium chloride lattice?

3. Chemical bonding  →  3.2. Ionic bonding

4. States of matter  →  4.2. Bonding and structure

2. Atoms, molecules and stoichiometry  →  2.3. Formulas

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5

A fluorescent light tube has an internal volume of 400 cm3 and an internal pressure of 200 kPa. It is filled with 0.03 moles of an ideal gas. What is the temperature of the gas inside the fluorescent light tube?

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

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6

One of the reactions in a lead / acid cell is shown...

18. Carboxylic acids and derivatives  →  18.1. Carboxylic acids

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

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

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7

Iodine and propanone react according to the following equation. I2+ CH3COCH3→ CH3COCH2I+ HIIf the concentration of propanone is increased, keeping the total reaction volume constant, the rate of the reaction also increases. What could be the reason for this?

8. Reaction kinetics  →  8.1. Rate of reaction

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

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8

Sulfur can be oxidised in two ways. S+ O2→ SO2∆H o = –296.5 kJ mol–1 2S+ 3O2→ 2SO3∆H o = –791.4 kJ mol–1 Sulfur trioxide can be made from sulfur dioxide and oxygen. 2SO2+ O2→ 2SO3What is the standard enthalpy change for this reaction?

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

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9

Hydrogen iodide dissociates into hydrogen and iodine. 2HIH2+ I2In an experiment, b mol of hydrogen iodide were put into a sealed vessel at pressure p. At equilibrium, x mol of the hydrogen iodide had dissociated. Which expression for Kp is correct?

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

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10

The diagram shows the distribution of molecular energies in a sample of gas at a temperature T1. The activation energy for an uncatalysed reaction of this gas, Ea, is shown...

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

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11

200 g of water are at 25 °C. The water is heated to 75 °C by burning 2 g of ethanol. What is the amount of energy transferred to the water?

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

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

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12

The elements Cl , Mg, Si and S are all in Period 3. What is the correct sequence of the melting points of these elements, from lowest to highest?

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

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

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13

An element Y reacts according to the following sequence. Y white solid solution solution white precipitate burns in O2 HCl NaOHan excess of NaOHWhat could be element Y?

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

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14

Which compound would most usually be added to soil to reduce its acidity?

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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15

The mineral dolomite is a mixture of magnesium carbonate and calcium carbonate. An aqueous reagent, X, was added to a small sample of dolomite. Effervescence was seen and a white solid, Y, was formed. What could be the correct identity of reagent X and solid Y?

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

3. Chemical bonding  →  3.2. Ionic bonding

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

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16

Which fertiliser contains the greatest percentage of nitrogen by mass?

12. Nitrogen and sulfur  →  12.1. Nitrogen and sulfur

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17

71.0 g of chlorine, Cl 2, react with an excess of sodium hydroxide solution at a particular temperature. The reaction produces exactly 35.5 g of product X. What is product X?

11. Group 17  →  11.4. The reactions of chlorine

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

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18

Compound Q is a white crystalline solid which dissolves easily in water. When concentrated sulfuric acid is added to a dry sample of Q steamy white fumes are formed which, when passed through aqueous silver nitrate solution, form a white precipitate. This precipitate is soluble in dilute ammonia solution. What could be the identity of compound Q?

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

12. Nitrogen and sulfur  →  12.1. Nitrogen and sulfur

4. States of matter  →  4.2. Bonding and structure

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19

The strengths of the covalent bonds within halogen molecules, and the van der Waals’ forces between halogen molecules, vary going down Group 17 from chlorine to bromine to iodine. Which row shows these correctly?

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

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

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20

The structural formula of compound Q is shown...

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

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

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21

What is the name of compound X?

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

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22

Many, but not all, organic reactions need to be heated before a reaction occurs. Which reaction occurs quickly at room temperature, 20 °C?

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

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23

A section of an addition polymer chain is shown...

20. Polymerisation  →  20.1. Addition polymerisation

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24

Which organic reaction is an example of nucleophilic substitution?

15. Halogen compounds  →  15.1. Halogenoalkanes

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

17. Carbonyl compounds  →  17.1. Aldehydes and ketones

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25

Citric acid can be converted into tricarballylic acid in two stages. An intermediate, Q, is formed. CH2 CO2H CO2H C Q HO CH2 CO2H citric acid CH2 CO2H CO2H CH CH2 CO2H tricarballylic acid stage 1 stage 2 Which reagents are needed for each stage?

18. Carboxylic acids and derivatives  →  18.1. Carboxylic acids

18. Carboxylic acids and derivatives  →  18.2. Esters

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26

Glucose can be used to prepare sorbitol, a compound used as a sugar substitute. HO OH OH OH OH OH sorbitol O H OH OH OH OH OH glucose Which reagent may be used for this conversion?

16. Hydroxy compounds  →  16.1. Alcohols

17. Carbonyl compounds  →  17.1. Aldehydes and ketones

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27

3-methylbutanone is treated with alkaline aqueous iodine. The mixture of products is then acidified. Which compound is present in the final mixture of products?

17. Carbonyl compounds  →  17.1. Aldehydes and ketones

18. Carboxylic acids and derivatives  →  18.1. Carboxylic acids

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28

At room temperature, propanoic acid was reacted to produce sodium propanoate. No gas was produced during the reaction. What could the propanoic acid have reacted with?

12. Nitrogen and sulfur  →  12.1. Nitrogen and sulfur

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

18. Carboxylic acids and derivatives  →  18.1. Carboxylic acids

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29

Ethene is reacted with steam in the presence of concentrated H3PO4. The product of this reaction is added to acidified potassium dichromate(and heated under reflux for one hour. The final organic product is collected and labelled X. But-2-ene is treated with hot, concentrated, acidified potassium manganate(. The final organic product is collected and labelled Y. Which statement is correct?

14. Hydrocarbons  →  14.2. Alkenes

14. Hydrocarbons  →  14.1. Alkanes

21. Organic synthesis  →  21.1. Organic synthesis

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30

A sample of the ester CH3CH2CH2CO2CH2CH3 is hydrolysed. The product mixture is then treated with hot, acidified KMnO4. What are the final carbon-containing products?

17. Carbonyl compounds  →  17.1. Aldehydes and ketones

14. Hydrocarbons  →  14.2. Alkenes

18. Carboxylic acids and derivatives  →  18.1. Carboxylic acids

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31

The definitions of many chemical terms can be illustrated by chemical equations. Which terms can be illustrated by an equation that includes the formation of a positive ion?

1. Atomic structure  →  1.4. Ionisation energy

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

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32

A student makes sodium chloride by reacting together 0.025 mol of sodium carbonate with an excess of 0.2 mol dm–3 hydrochloric acid. Na2CO3 + 2HCl → 2NaCl + H2O + CO2 Which statements about the quantities of substance are correct?

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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33

One way of recovering tin from old printed circuit boards is to dissolve it in a mixture of concentrated hydrochloric acid and concentrated nitric acid. The tin dissolves because it reacts with the mixture of these concentrated acids. Sn + 4HCl + 2HNO3 → SnCl 4 + NO2 + NO + 3H2O Which statements about this reaction are correct?

12. Nitrogen and sulfur  →  12.1. Nitrogen and sulfur

11. Group 17  →  11.4. The reactions of chlorine

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

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34

The following reaction takes place in a suitable solvent. Na+NH2 – + NH4 +Cl – → Na+Cl – + 2NH3 Which statements explain why this reaction should be classified as a Brønsted-Lowry acid-base reaction?

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

12. Nitrogen and sulfur  →  12.1. Nitrogen and sulfur

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35

Which statements about the elements barium and calcium and their compounds are 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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36

Which statements explain why nitrogen gas is unreactive?

12. Nitrogen and sulfur  →  12.1. Nitrogen and sulfur

14. Hydrocarbons  →  14.1. Alkanes

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37

In which molecules do all the carbon atoms lie in the same plane?

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

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38

A reaction pathway diagram is shown...

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

15. Halogen compounds  →  15.1. Halogenoalkanes

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39

The compounds below are used to make perfumes. Which compounds will produce a yellow precipitate with alkaline aqueous iodine?

16. Hydroxy compounds  →  16.1. Alcohols

17. Carbonyl compounds  →  17.1. Aldehydes and ketones

2. Atoms, molecules and stoichiometry  →  2.3. Formulas

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40

The reaction of ethanal, CH3CHO, with HCN to form 2-hydroxypropanenitrile is catalysed by NaCN. What are features of the intermediate of this reaction?

17. Carbonyl compounds  →  17.1. Aldehydes and ketones

19. Nitrogen compounds  →  19.2. Nitriles and hydroxynitriles

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