The following two reactions are known

Fe₂O_3(s) + 3CO_(g) $$ \to $$ 2Fe_(s) + 3CO_2(g); $$\Delta $$H = $$-$$ 26.8 kJ

FeO_(s) + CO(g) $$ \to $$  Fe_(s) + CO_2(g); $$\Delta $$H = $$-$$ 16.5 kJ

The value of $$\Delta $$H for the following reaction

Fe₂O_3(s) + CO_(g) $$ \to $$  2FeO_(s) + CO_2(g) is

For vaporization of water at 1 atmospheric pressure, the values of $$\Delta $$H and $$\Delta $$S are 40.63 kJ mol^$$-$$1 and 108.8 J K^$$-$$1 mol^$$-$$1, respectively. The temperature when Gibb's energy change ($$\Delta $$G) for this transformation will be zero, is

Three moles of an ideal gas expanded spontaneously into vacuum. The work done will be

For an endothermic reaction, energy of activation is E_a and enthalpy of reaction is $$\Delta $$H (both of these in kJ/mol). Minimum value of E_a will be