Question

What is efflorescence?

Answer 1

Efflorescence-

• It is a process when water is lost by the substance when exposed to air.
• The substance which loses its water of crystallisation when exposed to air is called Efflorescent substance.
• They are hydrated substances.

Example-

• Sodium sulphate loses all ten water molecules when exposed to air and forms white powder.
• $\underset{\mathrm{sodium}\mathrm{sulphate}}{{\mathrm{Na}}_2{\mathrm{SO}}_4.10{\mathrm{H}}_2\mathrm{O}}\left(\mathrm{s}\right)\stackrel{\mathrm{Exposed}\mathrm{to}\mathrm{air}}{\to }\underset{\mathrm{white}\mathrm{powder}}{{\mathrm{Na}}_2{\mathrm{SO}}_4\left(\mathrm{s}\right)}+10{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)$