Identifying the Products of Chemical Reactions (OCR Gateway GCSE Chemistry: Combined Science)

Exam Questions

32 mins19 questions
1a5 marks

Chemical tests are used to identify gases, anions and cations.

a)
 Draw lines to match the gas to the correct chemical test.

q16a-paper-2-specimen-2016-ocr-gcse-chem

[5]

1b3 marks
b)
A student uses the flame test to identify the cations in a solid.

Describe how she should do a flame test.
[3]

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1a1 mark

A student investigates a white solid.

Table 17.1 shows some of the results of the tests that the student does.

  Test Results
Test 1 flame test a lilac flame
Test 2 dilute hydrochloric acid added
gas given off passed into limewater
effervescence
?

Table 17.1

a)
Which ion is shown to be in the white solid by the result of Test 1?
[1]
1b4 marks
b)
The student reacts some metals with different salt solutions.

Table 17.2 shows her results.

  Magnesium Zinc Iron Copper
Copper sulfate blue solution
becomes
colourless
blue solution
becomes
colourless
blue solution
becomes
green
no reaction
Iron sulfate green solution
becomes
colourless
green solution
becomes
colourless
no reaction no reaction
Magnesium sulfate no reaction no reaction no reaction no reaction
Zinc sulfate black coating
on magnesium
no reaction no reaction no reaction

Table 17.2

i)
What colour is iron sulfate solution?

[1]

ii)
Write down the order of reactivity of the four metals copper, iron, magnesium and zinc.

Use Table 17.2 to help you.

........................................... most reactive
...........................................
...........................................
........................................... least reactive 

[2]

iii)
Magnesium reacts with copper sulfate, CuSO4.

Magnesium sulfate, MgSO4, and copper are made.

Write the balanced symbol equation for this reaction.

[1]

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23 marks

A student wants to identify the ions contained in a solid, X.

She dissolves the solid in some water and then does some tests on the solution.

Look at the table of her results.

Test Method Observations
Test 1 Flame test Red flame seen
Test 2 Add dilute sodium hydroxide solution White precipitate forms which re-dissolves in excess sodium hydroxide solution
Test 3

Add dilute nitric acid, then silver nitrate solution

White precipitate forms
Test 4

Add dilute hydrochloric acid, then barium chloride solution

No change – mixture stays clear and colourless

a)
Describe how the student does the flame test in Test 1.

You may draw a labelled diagram to help your answer.

[3]

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