Question

$5\cdot 1gN{H}_{4}SH$ is introduced in $3.0L$ evacuated flask at $327^{\circ }C.30\%$ of the solid $N{H}_{4}SH$ decomposed to $N{H}_3$ and $H_{2}S$ as gases. The $Kp$ of the reaction at $327{}^{\circ }C$ is
$(R=0\cdot 082L$ atm $mo{l}^{-1}{K}^{-1}$, Molar mass of $S=32gmol/{}^{01}$, molar mass of $N=14gmo{l}^{-1}$ )

• A. $1\times 10^{-4}at{m}^2$
• B. $4.9\times 10^{-3}at{m}^2$
• C. $0.242at{m}^2$
• D. $0.242\times 10^{-4}at{m}^2$

Answer 1

Answer: (C)

Now use $PV=nRT$ at equilibrium
$P_{\text{total }}\times 3$ lit $=(.03+.03)\times .082\times 600$
$P_{\text{total }}=.984atm$
At equilibrium
$P_{N{H}_3}=P_{H_{2}S}=\frac{P_{\text{total }}}{2}=.492$
$k_P=P_{N{H}_3}\cdot P_{H_{2}S}=(.492)(.492)$
$k_p=.242at{m}^2$