Question

The decomposition of solid ammonium carbamete, $\left(N{H}_4\right)\left(N{H}_{2}C{O}_2\right)$, to gaseous ammonia and carbon dioxide is an endothermic reaction.
$\left(N{H}_4\right)\left(N{H}_{2}C{O}_2\right)\left(s\right)\rightleftharpoons 2N{H}_3\left(g\right)+C{O}_2\left(g\right)$

When solid $\left(N{H}_4\right)\left(N{H}_{2}C{O}_2\right)$ is introduced into an evacuated flask at ${25}^{o}C$, the total pressure of gas at equilibrium is 0.116 atm. What is the value of $K_p$ at ${25}^{o}C$?

• A. $1.15\times {10}^4$
• B. $2.31\times {10}^4$
• C. $2.62\times {10}^4$
• D. None of these

Answer 1

Answer: (B)

$2.31\times {10}^4$

As given,
$N{H}_{2}COON{H}_4\left(s\right)\rightleftharpoons \underset{2P}{2N{H}_3\left(g\right)}+\underset{P}{C{O}_2\left(g\right)}$
$3P=0.116$
$K_P=4P^3=4{\left(\frac{0.116}{3}\right)}^3$
= $2.31\times {10}^4$