Question

Answer the questions below, relating your answers only to salts in the following list:

Sodium chloride, Anhydrous Calcium chloride, Copper sulphate-$5$-Water

(b) If Copper sulphate-$5$-Water is heated, the water is driven off, leaving anhydrous Copper sulphate.

(ii) By what means, other than heating, can you dehydrate Copper sulphate-$5$-Water and obtain anhydrous Copper sulphate?

Answer 1

Methods for dehydrating Copper sulfate-$5$-water:

• Adding dehydrating substances such as Concentrated Sulfuric acid $\left({\mathrm{H}}_2{\mathrm{SO}}_4\right)$ to the Copper sulfate -$5$-water, removes the Water $\left({\mathrm{H}}_2\mathrm{O}\right)$ from the compound and thus the compound becomes anhydrous.
• The chemical formula for anhydrous Copper sulfate is $\left({\mathrm{CuSO}}_4\right)$.

Use of anhydrous Copper sulfate:

• As a pesticide

By adding Concentrated Sulfuric acid $\left({\mathrm{H}}_2{\mathrm{SO}}_4\right)$ to Copper sulfate -$5$-water $\left({\mathrm{CuSO}}_4.5{\mathrm{H}}_2\mathrm{O}\right)$, anhydrous Copper sulfate $\left({\mathrm{CuSO}}_4\right)$ will be formed.

Chemical reaction:

• The chemical reaction is as follows

${\mathrm{CuSO}}_4.5{\mathrm{H}}_2\mathrm{O}\left(\mathrm{aq}\right)\stackrel{\mathrm{conc}.{\mathrm{H}}_2{\mathrm{SO}}_4}{\to }{\mathrm{CuSO}}_4\left(\mathrm{aq}\right)+5{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$