Question

The variation of K and $K_f$ as well as $K_b$ with temperature shows the following effects:
(i) For endothermic reaction K increases and $K_f$ as well as $K_b$ also increases with temperature.
(ii) For endothermic reaction K decreases and $K_f$ as well as $K_b$ also decreases with temperature.
(iii) For exothermic reaction K decreases and $K_f$ as well as $K_b$ both increases with temperature.
(iv) For exothermic reaction K increases and $K_f$ as well as $K_b$ decreases with temperature.
(v) For exothermic reaction K decreases and $K_f$ as well as $K_b$ both decreases with temperature.

• A. (i), (iii)
• B. (iii), (iv)
• C. (ii), (iii)
• D. (ii), (iii), (v)

Answer 1

Answer: (A)

(i), (iii)

As we know,
$E_a$ is always positive thus, rate constant increase with temperature.
$\Delta H$ is -ve, $\frac{K_f}{K_b}$ or $K_c$ decreases with temperature.

$\Delta H$ is +ve, $\frac{K_f}{K_b}$ or $K_c$ increases with temperature.