2024 May/June Cambridge O Level Science (Chemistry) - 14 MCQs

Which statement describes a liquid?

• Closely spaced particles able to move freely.

• Closely spaced particles vibrate about a fixed point.

• Particles are far apart and unable to move freely.

• Particles are far apart with large amounts of kinetic energy.

The diagram shows salt being added to water in a beaker. On which diagram are the labels correct?

• A

• B

• C

• D

An atom of element X contains 7 electrons. Which statements about atom X are correct?

1. X has a mass number greater than 7.

2. X is in Group 17 of the Periodic Table.

3. X is in Period 2 of the Periodic Table.

• 1, 2 and 3

• 1 and 2 only

• 1 and 3 only

• 2 and 3 only

Which statement about magnesium chloride, MgCl₂, is correct?

• When it is melted it becomes an electrical conductor because its electrons are free to move.

• It consists of anions and cations which have completely filled outer electron shells.

• It has a high melting point because its covalent bonds are very strong.

• The magnesium and chlorine atoms are bonded strongly together by sharing electrons.

Sodium metal reacts with water to produce hydrogen and a solution of sodium hydroxide. In which balanced equation are the state symbols correct?

• 2Na(s) + 2H₂O(aq) → 2NaOH(aq) + H₂(g)

• 2Na(s) + 2H₂O(aq) → 2NaOH(l) + H₂(g)

• 2Na(s) + 2H₂O(l) → 2NaOH(aq) + H₂(g)

• 2Na(s) + 2H₂O(l) → 2NaOH(l) + H₂(g)

The equation for the combustion of hydrogen is shown.

2H₂ + O₂ --> 2H₂O

Which mass of oxygen reacts when 2 g of hydrogen is burned in excess air?

• 1 g

• 16 g

• 32 g

• 64 g

Which statements about the combustion reaction between methane and oxygen are correct?

1 It is a cracking reaction.

2 It is an endothermic reaction.

3 It is an exothermic reaction.

4 It is a redox reaction.

• 1 and 2

• 1 and 3

• 2 and 4

• 3 and 4

1 g of solid zinc is reacted with excess dilute sulfuric acid in four different experiments under different conditions. The results are shown

Which row identifies the experiments taking the longest time and the shortest time for all the zinc to react?

• A

• B

• C

• D

Which test result identifies oxygen?

• bleaches damp litmus paper

• ‘pops’ with a lighted splint

• relights a glowing splint

• turns limewater milky

What is the colour of universal indicator in a neutral solution?

• blue

• green

• orange

• red