Question

What happen when crystals of washing soda ($Na_{2}CO_{3}.10H_{2}O$) are exposed to air?

Answer 1

The chemical formula for washing soda is given as ${ Na }_{ 2 }{ CO }_{ 3 }.10{ H }_{ 2 }O$. When${ Na }_{ 2 }{ CO }_{ 3 }.10{ H }_{ 2 }O$ exposed to air the water molecules gets absorbed by the sunlight. After absorption of the water molecules, the white powder results. The white powder is ${ Na }_{ 2 }{ CO }_{ 3 }$. This process of losing water molecules when "exposed to air" is called "efflorescence".