State the various statements of second law of thermodynamics.

30.4 kJ is required to melt one mole of sodium chloride. The entropy change during melting is 28.4 JK^-1 mol^-1. Calculate the melting point of sodium chloride.

Calculate the enthalpy of hydrogenation of ethylene from the following data. Bond energies of C - H, C - C , C = C and H - H are 414, 347, 618 and 435 kJ mol^-1

The standard enthalpies of formation of SO₂ and SO₃ are -297 kJ mol^-1 and -396 kJ mol^-1 respectively. Calculate the standard enthalpy of reaction for the reaction: SO₂ + \(\frac{1}{2}\)O₂⟶SO₃

Find out the value of equilibrium constant for the following reaction at 298K; 2NH_3(g)+ CO_2(g) \(\rightleftharpoons \) NH₂CONH_2(aq) + H₂O(I) Standard Gibbs energy change, \(\Delta { G }_{ r }^{ 0 }\) at the given temperature is -13.6 kJ mol^-1.