At 25$$^\circ$$C, the ionic product of water is 10$$^{-14}$$. The free energy change for the self-ionization of water in kCal mol$$^{-1}$$ is close to

Equal volumes of aqueous solution of $$0.1(\mathrm{M}) \mathrm{HCl}$$ and $$0.2(\mathrm{M}) \mathrm{H}_2 \mathrm{SO}_4$$ are mixed. The concentration of $$\mathrm{H}^{+}$$ ions in the resulting solution is

Correct solubility order of $$\mathrm{AgF}, \mathrm{AgCl}, \mathrm{AgBr}, \mathrm{AgI}$$ in water is

What will be the change in acidity if

(i) $$\mathrm{CuSO}_4$$ is added in saturated $$(\mathrm{NH}_4)_2 \mathrm{SO}_4$$ solution

(ii) $$\mathrm{SbF}_5$$ is added in anhydrous $$\mathrm{HF}$$