If the enthalpy change for the transition of liquid water to steam is 30 kJ mol^$$-$$1 at 27^oC, the entropy change for the process would be

Which of the following is correct option for free expansion of an ideal gas under adiabatic condition ?

Enthalpy change for the reaction,
4H_(g)  $$ \to $$  2H_2(g) is $$-$$869.6 kJ
The dissociation energy of H $$-$$ H bond is

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