Edexcel IGCSE Chemistry H Chemical Tests Questions

Practise chemical-test questions by matching reagents to ions or gases, recording observations and explaining clean-apparatus choices.

Exam points

Match flame-test colours, sodium hydroxide precipitates and anion reagents to ions.
Describe gas tests using splints, limewater or damp litmus and give the observation.
Explain why clean apparatus prevents contamination of flame-test or precipitate results.

Covered syllabus points

2.44 Gas tests 2.45 Flame-test method 2.46 Flame-test colours 2.47 Cation tests 2.48 Anion tests 2.49 Test for water 2.50 Water purity test

[Maximum number: 1]

A student uses this apparatus to investigate the decomposition of hydrogen peroxide solution.

Figure for Question 1 — Edexcel IGCSE Chemistry

This is the equation for the reaction.

2 \mathrm{H}_{2} \mathrm{O}_{2} \rightarrow 2 \mathrm{H}_{2} \mathrm{O}+\mathrm{O}_{2}

Give the test for oxygen.

[Maximum number: 6]

A student does these two tests on a solution made from a white solid.

- flame test
- add acidified silver nitrate solution

The table shows his results.

Table for Question 2 — Edexcel IGCSE Chemistry

(a)

Give the formula of the ion that produces the red flame.

[ 1 ]

$\mathrm{Li}^{+}$

ALLOW $\mathrm{Sr}^{2+}$

(b)

Name the cream precipitate.

[ 1 ]

(c)

Identify the white solid.

[ 1 ]

(d)

The student uses a clean metal wire in the flame test.

[ 3 ]

(i)

State why the wire should be clean when used in the flame test.

[ 1 ]

(ii)

The table lists properties of some metals.

Add ticks $(\checkmark)$ to the table to show the two properties needed in a metal wire used in a flame test.

Table for Question (ii) — Edexcel IGCSE Chemistry

[ 2 ]

[Maximum number: 2]

Describe a test to show that a solution contains $\mathrm{Fe}^{3+}$ ions

test

result

[Maximum number: 1]

A student does these two tests on a solution made from a white solid.

- flame test
- add acidified silver nitrate solution

The table shows his results.

Table for Question 4 — Edexcel IGCSE Chemistry

Give the formula of the ion that produces the red flame.

$\mathrm{Li}^{+}$

ALLOW $\mathrm{Sr}^{2+}$

[Maximum number: 2]

This question is about apparatus used in the laboratory.

The diagram shows apparatus used to obtain pure water from sodium chloride solution by simple distillation.

Figure for Question 5 — Edexcel IGCSE Chemistry

Describe a chemical test to show that the sodium chloride solution contains chloride ions.

M1 add silver nitrate/ $\mathrm{AgNO}_{3}$ (solution)

IGNORE addition of nitric acid but REJECT addition of hydrochloric/sulfuric acid for M1

M2 dep on use of silver nitrate

[Maximum number: 2]

A student uses this apparatus to investigate the decomposition of hydrogen peroxide solution.

Figure for Question 6 — Edexcel IGCSE Chemistry

This is the equation for the reaction.

2 \mathrm{H}_{2} \mathrm{O}_{2} \rightarrow 2 \mathrm{H}_{2} \mathrm{O}+\mathrm{O}_{2}

Give a chemical test for the presence of water.

- anhydrous / white copper(II) sulfate / copper sulfate / $\ce{CuSO4}$
- turns from white to blue

Allow:
- anhydrous / blue cobalt(II) chloride / cobalt chloride / cobalt(II) chloride paper
- turns from blue to pink

Ignore:
- water boils at 100 degrees C

- The colour-change mark depends on the reagent mark.

[Maximum number: 2]

This question is about apparatus used in the laboratory.

The diagram shows apparatus used to obtain pure water from sodium chloride solution by simple distillation.

Figure for Question 7 — Edexcel IGCSE Chemistry

Describe a physical test to show that the liquid in the conical flask is pure water.

All question bank results loaded

Covered syllabus points

Question 1

Question 2

Question (a)

Question (b)

Question (c)

Question (d)

Question (i)

Question (ii)

Question 3

Question 4

Question 5

Question 6

Question 7