The combination of plots which does not represent isothermal expansion of an ideal gas is –

For diatomic ideal gas in a closed system, which of the following plots does not correctly describe the relation between various thermodynamic quantities?

The standard reaction Gibbs energy for a chemical reaction at an absolute temperature T is given by $$\Delta $$_rG^o = A – BT

Where A and B are non-zero constants. Which of the following is TRUE about this reaction?

For the equilibrium,
2H₂O $$\rightleftharpoons$$ H₃O⁺ + OH^$$-$$, the value of $$\Delta $$G^o at 298 K is approximately :