Question

Name the compound whose one formula unit is associated with $10$ water molecules. How is it prepared? Give equations of related reactions. Give two uses of the compound.

Answer 1

The compound whose one formula unit is associated with $10$ water molecules is sodium carbonate decahydrate $\left({Na}_2{CO}_3.10H_{2}O\right)$ commonly known as washing soda.

It is prepared by heating baking soda and then recrystallizing the product so obtained.

The equations related to the above reaction is:

$2NaH{CO}_3\underset{}{\overset{\Delta }{\to }}{Na}_2{CO}_3+H_{2}O+{CO}_2$

${Na}_2{CO}_3+10H_{2}O\to {Na}_2{CO}_3.10H_{2}O$

Two uses of washing soda are:

(1) It is used in glass, soap and paper industries.

(2) It is used for removing the permanent hardness of water.