Chemistry
The salt which is the cause of hardness in water:
- Sodium sulphate
- Magnesium bicarbonate
- Sodium chloride
- Calcium nitrate
Answer
Magnesium bicarbonate
Reason — Hardness in water is due to the presence of bicarbonates, chlorides or sulphates of calcium or magnesium.
Sodium sulphate does not cause hardness because sodium salts are soluble and do not affect soap action. Sodium chloride is a common salt and does not cause hardness. Calcium nitrate is soluble but does not significantly contribute to hardness in the usual sense taught at this level.
Related Questions
Which of the following is a deliquescent salt ?
- CuSO4
- FeCl3
- KCl
- ZnSO4
If a salt on heating does not gives water vapour, then that salt is:
- Hygroscopic
- Deliquescent
- Hydrated
- Anhydrous
Temporary hardness of water can be removed by:
- Adding sodium chloride
- Boiling
- Adding calcium carbonate
- Leaving it for a few hours.
The salt which does not contain any water of crystallisation is :
P — Blue vitriol
Q — Gypsum
R — Baking soda
- Only P
- Only Q
- Only R
- Both Q and R