Required Practical 11
Required Practical 11: Carry out simple test-tube reactions to identify transition metal ions in aqueous solution
- This practical covers a number of key laboratory skills
- use water bath or electric heater or sand bath for heating
- use laboratory apparatus for a variety of experimental techniques
- safely and carefully handle solids and liquids, including corrosive, irritant, flammable and toxic substances
- The key to success in Required Practical 11 is following instructions carefully and recording coherent detailed observations of what you see
- The aim of the practical is to record the reactions of three unknown solutions, L, M and N
Key steps in the procedurePart 1
- 10 drops of solution L are added to a clean test tube
- Drops of dilute sodium hydroxide are added until in excess (i.e. you have exceeded 10 drops)
- Observations are recorded
- This procedure is then repeated with solution M and N
Part 2
- The test tubes from part 1 are place in a beaker of hot water for around 10 minutes
Part 3
- 10 drops of sodium carbonate solution are added to a clean test tube
- 10 drops of solution L are then added to the test tube and observations made
- The procedure is repeated with solution M and N
Part 4
- 10 drops of solution L are added to a clean test tube
- 10 drops of silver nitrate solution are then added to the test tube and observations made
- The procedure is repeated with solutions M and N and the tubes left to rest for around 10 minutes
Required Practical 11: Specimen Results Table Parts 1 & 2
Required Practical 11: Specimen Results Table Part 3
Required Practical 11: Specimen Results Table Part 4
Required Practical 11: Identities of solutions L, M and N
Practical Tip
- Always use clean test tubes and pipettes as the tests are very sensitive and you don't want to cross-contaminate the solutions
- It's a good idea to label your test tubes to avoid confusing ones that have the same appearance, especially when they are in a water bath and not arranged in a test tube rack
- To observe colour changes more clearly, using a white background such as a piece of paper can help
