The entropy change associated with the conversion of 1 kg of ice at 273 K to water vapours at 383 K is :

(Specific heat of water liquid and water vapour are 4.2 kJ K^$$-$$1 kg^$$-$$1 and 2.0 kJ K^$$-$$1 kg^$$-$$1; heat of liquid fusion and vapourisation of water are 334 kJ^$$-$$1 and 2491 kJ kg^$$-$$1, respectively). (log 273 = 2.436, log 373 = 2.572, log 383 = 2.583)

Consider the reversible isothermal expansion of an ideal gas in a closed system at two different temperatures T₁ and T₂ (T₁ < T₂). The correct graphical depiction of the dependence of work done (w) on the final volume (V) is :

For which of the following processes, $$\Delta $$S is negative ?

At 320 K, a gas A₂ is 20% dissociated to A(g). The standard free energy change at 320 K and 1 atm in J mol^-1 is approximately : (R = 8.314 JK^-1 mol^-1; ln2 = 0.693; ln 3 = 1.098)