Question

1. Name a reagent that will precipitate sulfate, phosphate, and carbonate ions.

2. Name a reagent that will dissolve BaCO3 and Ba3(PO4)2 but not BaSO4.

3. Name a reagent that will form a precipitate with chloride, phosphate, and carbonate ions but not with nitrate and sulfate ions.

4. Which one of the five anions that you will study liberates a gas when treated with HCl?

5. Which anion will not form a precipitate with any of the reagents that you are going to use?

Answer 1

1. Barium chloride.: A few drops of BaCl₂ to the few ml of the unknown solution, formation of white precipitate indicates either Sulphate, phosphate or carbonate.

2. To the acidified solution of the unknown, addition of BaCl2 will result in a white precipitate only if Sulphate is present. Phosphate and carbonates dissolved in the presence of acid.

3. Silver nitrate: Addition of silver nitrate results in the formation of insoluble precipitates of silver chloride, phosphate and carbonate when present

4. Carbonates when treated with HCl shows efferevescence (bubbles of gas)