Q1 / 150 · MHT CET 2022 (08 Aug Shift 1) · Chemistry
If the mixture of $7 g$ of $N_2$ and $8 g$ of $\mathrm{Ar}$ in a cylinder has the total pressure $27 \mathrm{bar}$. What is the partial pressure of $N_2$ ?
(Atomic mass of $N=14 \mathrm{~g} \mathrm{~mol}^{-1}, \mathrm{Ar}=40 \mathrm{~g} \mathrm{~mol}^{-1}$ )
- A18 bar
- B12 bar
- Correct answerC15 bar
- D9 bar
Solution
Moles of $N_2=\frac{7}{28}=\frac{1}{4}$
Moles of $\mathrm{Ar}=\frac{8}{40}=\frac{1}{5}$
Partial pressure $=X_{N_2} \times P_T$
Partial pressure of
$\begin{aligned}
N_2 & =\frac{\frac{1}{4}}{\frac{1}{4}+\frac{1}{5}} \times 27 \\
& =\frac{\frac{1}{4}}{\frac{9}{20}} \times 27 \\
& =\frac{1}{4} \times \frac{20}{9} \times 27 \\
& =15 \mathrm{bar}
\end{aligned}$
Hence, the correct answer is option: 'C'.