Question

A $34.1g$ sample of a copper (II) chloride hydrate was heated to drive off the water. The remaining anhydrous sample was $26.9g$. Find the number of waters hydration in the hydrate.

• A. $0.1$
• B. $0.2$
• C. $0.3$
• D. $0.4$

Answer 1

The correct option is D $0.4$

$CuC{l}_2.x{H}_{2}O$

Mass=$34.1g$

Molar mass=$134.45+x\times 18$

After dehydration mass remains= $26.9g$

Molar mass= $134.45$

Thus mass of $H_{2}O=34.1-26.9g$

$=7.2g$

Moles of $H_{2}O=\frac{7.2}{18}=0.4$ moles