Question

$1\text{g}$ of a metal on treatment with a dilute mineral acid gave $1242\text{mL}$ of hydrogen at STP. Calculate the equivalent weight of the metal.

• A. $18\text{g}$
• B. $20\text{g}$
• C. $9\text{g}$
• D. $15\text{g}$

Answer 1

The correct option is C $9\text{g}$

$22400\text{mL}$ of hydrogen gas at STP weighs $2\text{g}$ at STP
$1242\text{mL}$ of the gas at STP will weigh = $=\frac{2}{22400}\times 1242=0.11\text{g}$
$\frac{\text{weight of the metal}}{\text{weight of hydrogen}}=\frac{\text{equivalent weight of the metal}}{\text{equivalent weight of hydrogen}}$
$\Rightarrow \frac{1}{0.11}=\frac{M}{1}$
On solving, $M=9.09\text{g}$