Question

Zinc sulphate contains 22.65% Zn and 43.9% $H_{2}O$. If the law of constant proportions is true, then the mass of zinc required to give 40 g crystals will be:

• A. 90.6 g
• B. 9.06 g
• C. 0.906 g
• D. 906 g

Answer 1

The correct option is B 9.06 g

$ZnS{O}_4-22.65\%Zn$ $43.9\%H_{2}O$

$100g$ crystal has $22.65$ $Zn$

$40g$ crystal has $x$ $Zn$

$x=\frac{40\times 22.65}{100}=\frac{906}{100}=9.06g$

Hence, mass of $Zinc$ required is $9.06g$.