RP 11 Identifying transition metal ions

• How do transition metals undergo precipitation reactions?

  They react with hydroxide ions to form a metal hydroxide precipitate
• What can be reacted with transition metals for a precipitation reaction to occur?

  • Ammonia
  • Aqueous sodium hydroxide
• What is the first test that can be carried out to identify transition metal ions?

  • Place 10 drops of each solution (Q, R, S) in a test tube and add NaOH solution drop by drop to each until in excess. Record any observations.
  • Stand in a beaker of a hot water for 10 mins.
• What are the results for this practical?

  • Initial - Q: yellow solution, R: light blue solution, S: pale green solution
  • Add NaOH - Q: orange/brown precipitate, R: deep blue precipitate, S: grey/green precipitate
  • On standing in hot water - All: no visible change
• What is the second test that can be carried out to identify transition metal ions?

  • Add about 10 drops of each solution (Q, R, S) into a different test tube with Na2CO3(aq). Shake and record observations
• What are the results of this practical?

  Q: orange/brown precipitate and effervescence, R: blue/green precipitate, S: grey/green precipitate
• What can we conclude about Q, R and S?

  • Q - iron iii ions
  • R - copper ii ions
  • S - iron ii ions