2015 · Q22
When hard water is evaporated completely, the white solid remains in the container. It may be due to the presence of
- 1Carbonates of Ca and Mg
- 2Sulphates of Ca and Mg
- 3Chlorides of Ca and Mg
Select the correct answer using the code given below:
General KnowledgeChemistry
- A1 and 2 only
- B1, 2 and 3
- C3 only
- D1 and 3 only
Explanation
Hardness of water is caused by dissolved calcium and magnesium salts. When hard water is evaporated completely, all of them are left behind as a white solid — the carbonates (temporary hardness) as well as the sulphates and chlorides (permanent hardness). All three statements are correct — option B.