The reaction of cyanamide, NH₂CN_(s) with oxygen was run in a bomb calorimeter and $$\Delta$$U was found to be $$-$$742.24 kJ mol^$$-$$1. The magnitude of $$\Delta$$H₂₉₈ for the reaction

$$N{H_2}C{H_{(S)}} + {3 \over 2}{O_{2(g)}} \to {N_{2(g)}} + {O_{2(g)}} + {H_2}{O_{(I)}}$$

is _________ kJ. (Rounded off to the nearest integer) [Assume ideal gases and R = 8.314 J mol^$$-$$1 K^$$-$$1]

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.