Q.The standard entropy of $X_2, Y_2$ and $XY_3$ are $60, 40$ and $50 \text{ J K}^{-1} \text{ mol}^{-1}$ respectively. For the reaction $\frac{1}{2}X_2 + \frac{3}{2}Y_2 \rightleftharpoons XY_3$, $\Delta H = -30 \text{ kJ}$, to be at equilibrium, the temperature should be: