GCE A Level Chemistry H1 Online Mock Test: 2026

1. The hydrogen molecule contains a covalent bond. What holds the atoms together in this covalent molecule?

2.

Q2. The actual values of the masses of three sub-atomic particles are shown in the table:

Which nickel ion is predicted to have a mass of 1.038 × 10⁻²⁵ kg from these data?

3.

Which statement about 1 mol of a metal is always correct?

4. Which statement about this structure ice crystal is correct?

5.

The head of the first type of match, called a ‘lucifer’, contained a mixture of antimony(III) sulfide and potassium chlorate(V). When the match was ‘struck’, the following reaction took place:

Sb₂S₃(s) + 3KClO₃(s) → Sb₂O₃(s) + 3KCl(s) + 3SO₂(g)

Which element is reduced in the reaction?

6.

Use of the data booklet is relevant to this question.

The successive ionisation energies, in kJ mol⁻¹, of an element X are given:

870, 1800, 3000, 3600, 5800, 7000, 13200

What is X?

7.

Synthetic rubber is commonly produced from the monomer buta-1,3-diene.

What are the numbers of σ bonds and π bonds present in one molecule of buta-1,3-diene?

8.

Polymerisation of ethene gives poly(ethene).

How does the carbon-carbon bond in poly(ethene) compare with that in ethene?

9.

The elements phosphorus, sulfur and chlorine all exhibit covalent bonding. Their melting points are listed:

• phosphorus: 44°C
• sulfur: 115°C
• chlorine: −101°C

What accounts for these differences in melting points?

10. Which set of bond angles in pyruvic acid [ CH₃–CO–CO₂H ] would be predicted by Valence Shell Electron Pair Repulsion theory?

11.

The gases butane, 2-methylpropane and propane are kept in a sealed container at atmospheric pressure and room temperature.

Which row represents the order in which these gases will liquefy as the pressure in the container is gradually increased?

12.

Ammonia gas reacts with gaseous hydrogen chloride to form a white smoke of ammonium chloride.

Which statements correctly describe the behaviour of ammonia in this reaction?

1. It acts as an Arrhenius acid.
2. It acts as an Arrhenius base.
3. It acts as a Brønsted–Lowry acid.
4. It acts as a Brønsted–Lowry base.

13.

Which solution, when added to 25 cm³ of 0.100 mol dm⁻³ NaOH, produces a buffer solution?

14.

The table shows data on two acid-base indicators:

Which conclusion can be drawn about a solution in which:

• bromocresol green is blue
• phenol red is yellow

15.

When there is a small increase in the amount of CO₂(g) in the atmosphere, the pH of an ocean is maintained by a series of chemical reactions. Which equation maintains the pH in the ocean?

16.

Q16. Which row describes and explains the trend in electronegativity from fluorine to iodine?

17. Which diagram represents the change in ionic radius of the ions of the elements across the third period (Na to Cl)?

18. The diagram represents the Boltzmann distribution of molecular energies of a sample of gas at a given temperature.

As temperature increases, which statements are correct?

1. The maximum of the curve is displaced to the right.
2. The proportion of molecules with energies above any given value increases.
3. The proportion of molecules with any given energy increases.

19.

The conversion of diamond into graphite is slightly exothermic. Diamond does not readily change into graphite.

Which reaction pathway diagram correctly represents this conversion?

20.

Which statement about the effect of a catalyst on a system at equilibrium is correct?

21.

In the reaction between aqueous sodium thiosulfate and dilute acid:

• first order with respect to [acid] at low concentration
• zero order with respect to [acid] at high concentration

Which graph represents the experimental results?

22.

Q22. The use of catalytic converters in car exhaust systems reduces the amount of harmful nitrogen oxides emitted into the atmosphere.

Which statements about the catalytic converter are correct?

1. The catalyst is coated onto a honeycomb surface to provide a smaller surface area to increase the rate of the reaction.
2. The catalyst used is a heterogeneous catalyst which lowers the activation energy for the conversion of NO into N₂.
3. The forces of attraction holding the CO and NO molecules onto the surface of the catalyst are weaker than the forces of attraction holding the product molecules onto the surface.
4. Rhodium can be used as a catalyst in the catalytic converter.

23. In which reaction will the equilibrium yield of the right-hand product be increased by both of the indicated changes in pressure and temperature?

24.

Iodine trichloride, ICl₃, is made by reacting iodine with chlorine. Given:

Find standard enthalpy of formation of solid ICl₃.

25.

The equation for the complete combustion of ethanethiol is:

A 20 cm³ sample of ethanethiol vapour is ignited with 100 cm³ of oxygen. After burning, the gas is cooled to room temperature. The cooled gas is then treated with excess aqueous alkali. What percentage of the final volume of cooled gas dissolves in the alkali?

26.

What is the skeletal formula for 2,2,3-trimethylpentane?

27.

Which molecular formulae could represent molecules that exhibit cis-trans isomerism?

1. C₃H₆BrI
2. C₃H₅I
3. C₃H₄I₂
4. C₃H₄BrI

28.

29.

30.

When egg white is heated, protein molecules are denatured. Which statements describe what happens in this process?

• The hydrogen bonds and induced dipole interactions are broken.
• The peptide bonds are broken by hydrolysis.
• The three-dimensional structure of the molecule changes.