Question

Radiolysis of water yields $H_2$ as given below:
$2H_{2}O⟶H_2{O}_2+H_2$
In the analysis, it is found that $1.7$ molecules of $H_2$ are produced per $100$ eV of energy absorbed. A nuclear power reactor of $200$ kW capacity has been installed based on this reaction.

What mass of heavy water is required to yield $448$ kilolitres of heavy hydrogen at STP?

• A. $996$ kg
• B. $448$ kg
• C. $800$ kg
• D. $720$ kg

Answer 1

The correct option is C $800$ kg

$448$ kL of heavy hydrogen at STP corresponds to $\frac{448000}{22.4}=20000$ mol of hydrogen.

From the balanced chemical equation, $2H_{2}O⟶H_2{O}_2+H_2$, it can be seen that $1$ mol of hydrogen is formed from $2$ mol of heavy water.

Hence, $20000$ mol of hydrogen will be formed from $40000$ mol of heavy water.

The molar mass of heavy water is $20$ g/mol.

Hence, $40000$ moles of heavy water corresponds to $40000$ moles $\times 20$ g/mol $=800000$ g $=800$ kg.

Thus, $800$ kg of heavy water is required to yield $448$ kL of heavy hydrogen at STP.