Standard entropies of X₂, Y₂ and XY₃ are 60, 40 and 50 J K^$$-$$1 mol^$$-$$1 respectively. For the reaction

1/2X₂ + 3/2Y₂ $$\rightleftharpoons$$ XY₃, $$\Delta $$H = $$-$$ 30 kJ,

to be at equilibrium, the temperature should be

From the following bond energies :
H $$-$$ H bond energy   : 431.37 kJ mol^$$-$$1
C $$=$$ C bond energy   : 606.10 kJ mol^$$-$$1
C $$-$$ C bond energy   : 336.49 kJ mol^$$-$$1
C $$-$$ H bond energy   : 410.50 kJ mol^$$-$$1
Enthalpy for the reaction,

will be

The values of $$\Delta $$H and $$\Delta $$S for the reaction,

C_(graphite) + CO₂(g) $$ \to $$  2CO_(g)

are 170 kJ and 170 J K^$$-$$1, respectively. This reaction will be spontaneous at

Bond dissociation enthalpy of H₂, Cl₂ and HCl are 434, 242 and 431 kJ mol^$$-$$1 respectively. Enthalpy of formation of HCl is