Hydrazine used in rocket fuels can be obtained by the reaction of ammonia and hydrogen peroxide according to the equation $$2NH_3 (g) + H_2O_2 (l) \rightarrow N_2H_4 (l) + 2H_2O (l)$$ with $$\Delta H^0_{reaction} = -241$$ $$\text{kJ mol}^{-1}$$. If $$\Delta H^0$$ of formation of $$NH_3$$, $$H_2O_2$$ and $$H_2O$$ are $$-46.1$$, $$-187.8$$ and $$-285.8$$ $$\text{kJ mol}^{-1}$$ respectively, $$\Delta H^0$$ for the decomposition of hydrazine into $$N_2$$ and $$H_2$$ is