For the reaction \(N_2(g) + 3H_2(g) \rightleftharpoons 2\text{NH}_3(g)\) at 298 K, the enthalpy change \( \Delta H = -92.4 \, \text{kJ/mol} \). What happens to the equilibrium when temperature is increased?
- The reaction is: \( \text{N}_2(g) + 3\text{H}_2(g) \rightleftharpoons 2\text{NH}_3(g) \), with \( \Delta H = -92.4 \, \text{kJ/mol} \).
- Since \( \Delta H < 0 \), the reaction is exothermic (releases heat).
- According to Le Chatelier’s principle, for an exothermic reaction, increasing the temperature favors the endothermic direction (reverse reaction) to absorb the added heat.
Here, the reverse reaction is: \( 2\text{NH}_3(g) \rightarrow \text{N}_2(g) + 3\text{H}_2(g) \), which is endothermic.
Thus, increasing the temperature shifts the equilibrium to the left (towards reactants).
This matches option (B).
For the reaction: $A_2(g) \rightleftharpoons B_2(g)$
The equilibrium constant $K_c$ is given as 99.0. In a 1 L closed flask, two moles of $B_2(g)$ is heated to $T(K)$. What is the concentration of $B_2(g)$ (in mol L$^{-1}$) at equilibrium?
At 1000 K, the value of $K_c$ for the below reaction is $10 \text{ mol L}^{-1}$. Value of $K_p$ (in atm) is (given $R = 0.082 \text{ atm L mol}^{-1} \text{K}^{-1}$)
${\{A(g) <=> B(g) + C(g)}$