C3 - Tests for negative ions

Testing for carbonates - check for CO2
1. You can test to see if a gas is carbon dioxide by bubbling it through limewater. If it is carbon dioxide, the limewater turns cloudy
2. You can use this to test for carbonate ions since carbonate react with dilute acids to form carbon dioxide
  1. acid + carbonate = salt + water + carbon dioxide
Tests for halides
1. To test for chloride,bromide or iodide, add dilute nitric acid followed by silver nitrate solution
  1. Chloride gives a white precipitate of silver chloride
  2. Bromide gives a cream precipitate of silver bromide
  3. Iodide gives a yellow precipitate of silver iodide.
To test for sulphate ions
1. Add dilute HCl followed by barium chloride solution
2. A white precipitate of barium sulphate means the original compound was a sulphate.

Resource summary

	Created by Lily O'Brien almost 8 years ago