Question

If a mixture containing $3$ moles of hydrogen and $1$ mole of nitrogen is converted completely into ammonia, the ratio of initial and final volume under the same temperature and pressure would be

• A. $3:1$
• B. $1:3$
• C. $2:1$
• D. $1:2$

Answer 1

The correct option is C $2:1$

The reaction for conversion is

$N_2+{3H}_2\to {2NH}_3$

Here, $n_1=3+1=4n_2=2Initialvolume=V_{1}FinalVolume=V_2$

Applying Avagadro's Law, we get

$\frac{V_1}{n_1}=\frac{V_2}{n_2}\frac{V_1}{V_2}=\frac{n_1}{n_2}\frac{V_1}{V_2}=\frac{4}{2}=\frac{2}{1}So,V_1:V_2=2:1$.

So, correct answer is option $C$.