Question

For a reaction $A\left(g\right)\rightleftharpoons B\left(g\right)+C\left(g\right).K_p$ at ${400}^{o}C$ is $1.5\times {10}^{-4}$ and $K_p$ at ${600}^{o}C$ is $6\times {10}^{-3}$. Which statement is incorrect?

• A. The reaction is exothermic
• B. Increase in temperature increases the formation of B.
• C. Increase in pressure increases the formation of A.
• D. Decrease in temperature and increase in pressure shift the equilibrium towards left.

Answer 1

The correct option is A The reaction is exothermic

$A\left(g\right)\rightleftharpoons B\left(g\right)+C\left(g\right)$
a. With increase of temperature $K_p$ increases, i.e., with increase of temperature, the reaction is favoured in forward direction and hence reaction is endothermic, Thus statement (a) is incorrect.
b. Increase of temperature favours forward reaction and hence the formation of B increases. Correct statement.
c. $\Delta n=1+1-1=1$
$\Delta n=-ve$, i.e., with the increase of pressure, reaction is favoured backward direction and hence the formation of A(g) increases. Correct statement.
d. As from the above statement in (i) and (iii), the reaction is favoured backward with decrease of temperature and increase of pressure. Correct statement.