Question

The number of molecules of water of crystallization present in one molecule of ferrous sulfate is_______.

• A. $5$
• B. $7$
• C. $6$
• D. $10$

Answer 1

The correct option is B $7$

When water is used in the formation of crystals knows as water of crystallization.

The water of crystallization is the total weight of water in a substance at a given temperature and is mostly present in a definite ratio.

On heating, iron(II) sulfate first loses its water of crystallization and the original green crystals are converted into a brown-colored anhydrous solid.

$FeS{O}_4.7H_{2}O$ is the heptahydrate in solution (water as solvent) transforms to both heptahydrate and tetrahydrate when the temperature reaches ${56.6}^{\circ }C$.

Hence, option $B$ is correct.