Question

Name the salts that cause hardness of water.

Answer 1

Hard water

• The presence of specific dissolved Calcium $\left(\mathrm{Ca}\right)$ and Magnesium $\left(\mathrm{Mg}\right)$ salts in water causes water to be hard.
• Hard water does not produce lather with soap.
• These following are the salts that causes hardness in water.

1. Calcium sulphate $\left({\mathrm{CaSO}}_4\right)$
2. Magnesium sulphate $\left({\mathrm{MgSO}}_4\right)$
3. Calcium chloride $\left({\mathrm{CaCl}}_2\right)$
4. Calcium bicarbonate $\left[\mathrm{Ca}{\left({\mathrm{HCO}}_3\right)}_2\right]$
5. Magnesium bicarbonate $\left[{\mathrm{Mg}\left({\mathrm{HCO}}_3\right)}_2\right]$
6. Magnesium chloride $\left({\mathrm{MgCl}}_2\right)$