Question

How many litres of ammonia gas at S.T.P. would be needed to prepare $100mL$ of $2.5M$ ammonium hydroxide solution?

• A. $5.6L$
• B. $0.056L$
• C. $11.2L$
• D. $0.56L$

Answer 1

The correct option is A $5.6L$

$N{H}_3+H_{2}O⟶N{H}_{4}OH$

Given,

$\left[N{H}_{4}OH\right]=2.5M=\frac{x}{35}\times \frac{1000}{100}$

$\therefore x=8.75$

Now moles of $N{H}_{4}OH=\frac{8.75}{35}=0.25$

$1$ mole of $N{H}_3$ produces one mole of $N{H}_{4}OH$

$\therefore 0.25$ mole of $N{H}_{4}OH$ will be produced from $0.25$ moles of $N{H}_3$

$\therefore$ Volume $=0.25\times 22.4=5.6L$ of $N{H}_3$

Hence, the correct option is $A.$