Question

Give reason for the following:

Silica gel is used in closed boxes or medicine bottles.

Answer 1

Desiccants-

They are known as hygroscopic substances or dry 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-

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

Silica gel is used in closed boxes or medicine bottles-

• It is a dry agent.
• It is a porous form of silicon dioxide.
• Due to its porous form, it holds moisture.
• Due to moisture, medicine quality will get affect affected.
• To keep them dry and hold moisture, silica gel is used in medicine bottles.