Standard entropies of  $$X_2,\ Y_2$$  and  $$XY_5$$  are  $$70,\ 50$$  and  $$110\,J\,K^{-1}mol^{-1}$$ respectively. The temperature in Kelvin at which the reaction $$\frac{1}{2}X_2 + \frac{5}{2}Y_2 \rightleftharpoons XY_5 \Delta H^\ominus = -35\,kJ\,mol^{-1}$$ will be at equilibrium is $$\underline{\hspace{2cm}}$$  (Nearest integer).}