The ionization enthalpy of Na⁺ formation from Na_(g) is 495.8 kJ mol^$$-$$1, while the electron gain enthalpy of Br is $$-$$325.0 kJ mol^$$-$$1. Given the lattice enthalpy of NaBr is $$-$$728.4 kJ mol^$$-$$1. The energy for the formation of NaBr ionic solid is ($$-$$) ____________ $$\times$$ 10^$$-$$1 kJ mol^$$-$$1.

Assuming ideal behaviour, the magnitude of log K for the following reaction at 25$$^\circ$$C is x $$\times$$ 10^$$-$$1. The value of x is ______________. (Integer answer)

$$3HC \equiv C{H_{(g)}} \rightleftharpoons {C_6}{H_{6(l)}}$$

[Given : $${\Delta _f}{G^o}(HC \equiv CH) = - 2.04 \times {10^5}$$ J mol^$$-$$1 ; $${\Delta _f}{G^o}({C_6}{H_6}) = - 1.24 \times {10^5}$$ J mol^$$-$$1 ; R = 8.314 J K^-1 mol^$$-$$1]

For a dimerization reaction,
2A(g) $$ \to $$ A₂(g)
at 298 K, $$\Delta $$U^o = –20 kJ mol^–1, $$\Delta $$S^o = –30 JK^–1 mol^–1,
then the $$\Delta $$G^o will be _____ J.

The heat of combustion of ethanol into carbon dioxide and water is – 327 kcal at constant pressure. The heat evolved (in cal) at constant volume and 27^oC (if all gases behave ideally) is (R = 2 cal mol^–1 K^–1) ________.