Question

Give reason for the following:

What will happen if calcium chloride (${\mathrm{CaCl}}_2$) is left exposed to air?

Answer 1

Desiccants-

They are known as hygroscopic substances or drying agents.

Hygroscopy-

• It is a process in which water is absorbed from the air, but it is not enough to change the state of the substance.
• The substance which follows this process is called a hygroscopic substance.

Examples-

• Calcium oxide $\left(\mathrm{CaO}\right)$
• Calcium chloride $\left({\mathrm{CaCl}}_2\right)$
• Sodium sulphate $\left({\mathrm{Na}}_2{\mathrm{SO}}_4\right)$

If calcium chloride (${\mathrm{CaCl}}_2$) is left exposed to air-

• As it is a drying agent so it will absorb sufficient water from the air to allow it to dissolve.
• Solid white calcium chloride will change into a clean liquid.