How are equations used to represent chemical reactions? test questions - OCR 21st Century - GCSE Combined Science Revision

1

What is the correct formula of methane?

ch₄

Ch₄

CH₄

2

Sodium is in group 1. What is the charge of its ion?

-1

+1

+2

3

What is the charge of non-metal ions in group 7?

-1

+1

-2

4

What is the correct formula for aluminium chloride, which contains Al³⁺ and Cl^– ions?

Al₃Cl

AlCl₃

Al₃Cl₃

5

What is the name of an OH^- ion?

Water ion

Hydroxide

Oxyhydrogen

6

What is the correct formula for sodium hydroxide?

NaOH

Na(OH)₂

Na₂OH

7

What is the name of the ion with formula SO₄^2-?

Sulfide

Sulfur

Sulfate

8

What is the meaning of the state symbol (aq)?

Aqua

Aquatic

Aqueous

9

Which state symbol should be used for bubbles of hydrogen?

(s)

(l)

(g)

10

Which equation is correctly balanced?

2Mg + CuCl₂ → MgCl₂ + Cu

Mg + CuCl₂ → MgCl₂ + Cu

Mg + CuCl₂ → MgCl₂ + 2Cu