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)

The combustion of benzene(l) gives CO₂(g) and H₂O(l). Given that heat of combustion of benzene at constant volume is –3263.9 kJ mol^–1 at 25^oC; heat of combustion (in kJ mol^–1) of benzene at constant pressure will be :
(R = 8.314 JK^–1 mol^–1)