Question

1 mol of $NaCl{O}_4$ is to be produced from the electrolysis of $NaCl{O}_3$. Find the volume of $H_2$ evolved at STP in the time during which 12.25 g of $NaC{l}_4$ are produced.

• A. 1.12 L
• B. 2.24 L
• C. 2.56 L
• D. 5.12 L

Answer 1

Answer: (B)

2.24 L

$NaCl{O}_3+H_{2}O\to NaCl{O}_4+2H^{\oplus }+2e^{-}$

$2H^{\oplus }+2e^{-}\to H_2$

2 F = 1 mol $NaCl{O}_4$
$\Rightarrow$ Number of Faradays required = 2

$\frac{12.5}{122.5}molNaCl{O}_4=2\times \frac{12.5}{122.5}F=0.2F$

$\Rightarrow$ 0.2 F are liberated.

2 F = 1 mol $H_2$
$\Rightarrow$ Moles of $H_2$ produced = 0.1

Volume of $H_2=2.24$ L.