Question

Match the following hydrates with the type of water involved.

• A. Co-ordinated water
• B. Hydrogen bond water
• C. Interstitial water

Answer 1

Water combines with many salts during crystallisation to form hydrated salts and the water present in these hydrates is called water of crystallisation.
Water of crystallisation can be of three types. They are:

1. Co-ordinated water
2. Interstitial water
3. Hydrogen bonded water

According to their definitions, types of water for given hydrates are:
${\left(\mathrm{Cr}{\left(H_{2}O\right)}_6\right]}^{3+}.3{\mathrm{Cl}}^{-}$ - Co-ordinated water
${\mathrm{BaCl}}_2.2H_{2}O$ - Interstitial water

${\mathrm{CuSO}}_4.5H_{2}O$ - Hydrogen bond water