Question

Equal volumes of $H_2$ and $C{l}_2$ are mixed. How will the volume of the mixture changes after the reaction at same T and P?

• A. Unchanged
• B. Reduced to half
• C. Increases two fold
• D. None of these

Answer 1

The correct option is A Unchanged

According to Avogadro's hypothesis, under the conditions of same temperature and pressure,
$Volume\propto \text{number of moles}$

$H_{2\left(g\right)}+C{l}_{2\left(g\right)}\to 2HC{l}_{\left(g\right)}$
$$\begin{array}{cccc}t=0& 1& 1& 0\\ t=completion& -& -& 2\end{array}$$
Since the number of moles of the product is equal to the number of moles of the reactant, there is no change in the number of moles and hence there is no change in the volume.