Required Practical 11 (AQA A Level Chemistry): Revision Note

Required Practical 11

Objective

To carry out simple test–tube reactions to identify transition metal ions in aqueous solution.

Apparatus

Method

Test 1 - part a

• Note the initial colour of solution Q

• Place 10 drops of solution Q in a test tube

• Add sodium hydroxide solution, dropwise with gentle shaking, until in excess

  • Keep the test tube for part b

• Record any observations in an appropriate table

• Repeat this test with solutions R and S

Test 1 - part b

• Half fill a 250 cm³ beaker with freshly boiled water

• Stand the three test tubes from part a in the beaker of hot water for about 10 minutes

• Record any observations in an appropriate table

Test 2

• Place 10 drops of sodium carbonate solution in a test tube

• Add 10 drops of solution Q

  • Shake the mixture gently

• Record any observations in an appropriate table

• Repeat this procedure with solutions R and S

Test 3

• Place about 10 drops of solution Q in a test tube

• Add about 10 drops of silver nitrate solution and shake the mixture gently

• Repeat this procedure with solutions R and S

• Allow the three test tubes to stand for about 10 minutes

• Record any observations in an appropriate table

Results

• The results for this required practical are the observations of solutions Q, R and S in tests 1, 2 and 3

• A suitable results table could be:

Evaluation

• The results from all three tests are used to identify the ions present in solutions Q, R and S

Practical Tip

• Always use clean test tubes and pipettes, as many chemical tests are highly sensitive, and contamination can affect the results

• Label test tubes clearly to avoid confusion, particularly when solutions have a similar appearance or when test tubes are placed in a water bath

• Use a white background, such as a sheet of paper, to observe colour changes more clearly