Question

3. Which of the following salts is the main cause of permanent hardness of water?
(a) Magnesium sulphate
(b) Magnesium bicarbonate
(c) Magnesium carbonate
(d) None of the above​

Answer 1

Answer:

magnesium sulfate or calcium sulfate

Explanation:

The permanent hardness of water is caused due to the presence of magnesium, sulfide and calcium in water. It is known as permanent hardness because it cannot be removed by boiling.

Answer 2

Answer:

a)  Magnesium sulphate is the main cause of permanent hardness of water.

Explanation:

• The amount of dissolved calcium and magnesium in the water is the simplest definition of water hardness.
• The presence of calcium and magnesium chlorides, nitrates, and sulphates, particularly Magnesium sulphate, causes permanent hardness in water.
• The permanent hardness of water is mainly due to the presence of sulphate in it.