Name the two salts which makes the water hard.

Q. Name a white crystalline solid salt used to make hard water soft and potable.

Q. Which of the following salts will cause temporary hardness of water?

Q. A student requires hard water for an experiment in his laboratory which is not available in the neighbouring area. In the laboratory there are hard water. Select from the following groups of salts, a group, each salt of which when dissolved in distilled water will make it hard.

Q. A student requires hard water for an experiment in his laboratory which is not available in the neighbouring area. In the laboratory there are some salts, which when dissolved in distilled water can convert it into hard water. Select from the following groups of salts, which when dissolved in distilled water will make it hard.
(a) Sodium chloride, Potassium chloride
(b) Sodium sulphate, Potassium sulphate
(c) Sodium sulphate, Calcium sulphate
(d) Calcium sulphate, Magnesium chloride