Question

One mole of nitrogen gas on reaction with $3.01 \times 10^{23}$ molecules of hydrogen gas produces

• A. one mole of ammonia
• B. $2.0 \times 10^{23}$ molecules of ammonia
• C. 2 moles of ammonia
• D. $3.01 \times 10^{23}$ molecules of ammonia

Answer 1

Answer: (B)

$N _{2}+3 H _{2} \rightleftharpoons 2 NH _{3}$
$6.022 \times 10^{23}$ molecules of $H _{2}=1$ mole
$\therefore 3.011 \times 10^{23}$ molecules of $H _{2}=0.5$ mole.
$3$ moles of $H _{2}$ reacts with $2$ moles of $NH _{3}$.
So, $1$ mole of $H _{2}$ reacts $=\frac{2}{3}$ moles of $NH _{3}$.
$\therefore 0.5$ mole of $H _{2} \text { react with } \frac{2}{3} \times 0.5$
$=\frac{1}{3} mole$
$1$ mole of $NH _{3}$ contains $6.022 \times 10^{23}$ molecules.
So, $\frac{1}{3}$ mole of $NH _{3}$ will have
$=6.022 \times 10^{23} \times \frac{1}{3}$
$=2.0 \times 10^{23}$ molecules.