Dehydration of salts is an important class of heterogeneous reactions. The salt hydrates during dehydration often dissociate in steps to form a number of intermediate hydrates according to the prevailing pressure of moisture in contact with the solid hydrates. Thus, copper sulphate pentahydrate on dissociation yield trihydrates, monohydrates and then the anhydrous salt in the above order as follows:

Which of the following conditions is favourable for dehydration of `CuCO_(4). 5H_(2)O`?
i. Low humidty in air
ii. High temperature
iii. `p_(H_(2)O)` increases
The correct option is:

Options

A. i
B. i, ii
C. ii, iii
D. i, ii, iii

Answer

B

Explanation

Dehydration of `CuSO_(4).5H_(2)O` is favourable at low humidity in air, high temperature and it decreases with increasing partial pressure of water vapour i.e. `p_(H_(2)O)`