OCR Gateway GCSE Combined Science June 2022 Paper 3: timed practice

4 marksFoundation

Spec and skills

Original practice question
Answer and supported method checks

Some substances are listed below. Copper, carbon dioxide, air, sodium chloride.

.1

Which substance is an element?

[1 mark]

.2

Which substance is a mixture?

[1 mark]

.3

Give the number of different elements in the formula

\mathrm{CaCO_{3}}

.

[1 mark]

.4

A student has a mixture of sand and water. Choose the best method to get the sand.

[1 mark]

3 marksFoundation

Spec and skills

Original practice question
Answer and supported method checks

Diamond is used in drill bits for cutting through rock.

.1

Give the number of covalent bonds each carbon atom forms in diamond.

[1 mark]

.2

Explain why diamond is very hard.

[2 marks]

4 marksFoundation

Spec and skills

Original practice question
Answer and supported method checks

Relative atomic masses (

A_r

): H = 1, C = 12, O = 16, Mg = 24, Cl = 35.5

.1

Calculate the relative formula mass (

M_r

) of water,

\mathrm{H_{2}O}

.

[1 mark]

.2

Calculate the

M_r

of carbon dioxide,

\mathrm{CO_{2}}

.

[1 mark]

.3

Calculate the

M_r

of magnesium chloride,

\mathrm{MgCl_{2}}

.

[2 marks]

3 marksFoundation

Spec and skills

Original practice question
Answer and supported method checks

Acids react with metals, bases and carbonates to make salts.

.1

Name the salt made when magnesium oxide reacts with hydrochloric acid.

[1 mark]

.2

Name the salt made when sodium hydroxide reacts with sulfuric acid.

[1 mark]

.3

Name the gas produced when calcium carbonate reacts with hydrochloric acid.

[1 mark]

3 marksFoundation

Spec and skills

Original practice question
Answer and supported method checks

Chemical reactions can transfer energy to or from the surroundings.

.1

Which two reactions are exothermic? Tick two boxes.

[2 marks]

.2

Give one everyday use of an endothermic reaction.

[1 mark]