Question

The difference of water molecules in gypsum and plaster of Paris is:

• A. $\frac{5}{2}$
• B. $2$
• C. $\frac{1}{2}$
• D. $1\frac{1}{2}$

Answer 1

The correct option is D $1\frac{1}{2}$

Gypsum: $CaS{O}_4.2H_{2}O$ and

Plaster of Paris: $CaS{O}_4\frac{1}{2}{H}_{2}O$

Difference of Water = $2-\frac{1}{2}=\frac{3}{2}=1\frac{1}{2}$