Question

Question #1b658

Answer 1

The solution is to select an ion that will form a precipitate or gas with one of the ions while leaving the other in solution.

Explanation:

A list of useful solubility rules follows:

1. All compounds of the ammonium ion (NH4+), and of Alkali metal (Group IA) cations (sodium, potassium, etc.), are soluble.
2. All nitrates, perchlorates and acetates (ethanoates) are soluble.
3. All chlorides, bromides and iodides are soluble EXCEPT those of silver, lead and mercury(I).
4. All sulphates are soluble EXCEPT those of silver, lead, mercury(I), barium, strontium and calcium.
5. All carbonates, sulfites and phosphates are insoluble EXCEPT those of ammonium and Alkali metal (Group IA) cations.
6. All hydroxides are insoluble EXCEPT those of ammonium, barium and alkali metal (Group I) cations.
7. All sulfides are insoluble EXCEPT those of ammonium, Alkali metal (Group I) cations and Alkali earth metal (Group II) cations.
8. All oxides are insoluble EXCEPT those of calcium, barium and Alkali metal (Group I) cations; these soluble ones actually react with the water to form hydroxides (hydrolyse).