Question

When $5.1g$ of solid $N{H}_{4}HS$ is introduced into a two litre evacuated flask at $27^{\circ }C,20\%$ of the solid decomposes into gaseous ammonia and hydrogen sulphide. The $K_p$ for the reaction at $27^{\circ }C$ is $x\times 10^{-2}$. The value of $x$ is ________. (Integer answer)
$[$ Given $R=0.082Latm{K}^{-1}mo{l}^{-1}]$

Answer 1

Answer: 6

moles of $N{H}_{4}HS$ initially taken $=\frac{5.1g}{51g/mol}$
$=0.1mol$
volume of vessel $=2\ell$

$\Rightarrow$ partial pressure of each component
$P=\frac{nRT}{V}=\frac{0.1\times 0.2\times 0.082\times 300}{2}$
$=0.246atm$
$\Rightarrow k_P=P_{N{H}_3}\times P_{H_{2}S}$
$=(0.246{)}^2=0.060516$
$=6.05\times 10^{-2}$
$\Rightarrow 6$