Two salts A₂X and MX have the same value of solubility product of 4.0 $$\times$$ 10^$$-$$12. The ratio of their molar solubilities i.e. $${{S({A_2}X)} \over {S(MX)}}$$ = __________. (Round off to the Nearest Integer)

For the reaction $$A(g) \rightleftharpoons B(g)$$ at 495 K, $$\Delta$$_rG$$^\circ$$ = $$-$$9.478 kJ mol^$$-$$1.
If we start the reaction in a closed container at 495 K with 22 millimoles of A, the amount of B in the equilibrium mixture is ____________ millimoles.
(Round off to the Nearest Integer). [R = 8.314 J mol^$$-$$1 K^$$-$$1; ln 10 = 2.303]

When 12.2 g of benzoic acid is dissolved in 100 g of water, the freezing point of solution was found to be $$-$$0.93$$^\circ$$C (K_f(H₂O) = 1.86 K kg mol^$$-$$1). The number (n) of benzoic acid molecules associated (assuming 100% association) is ___________.

The pH of ammonium phosphate solution, if pk_a of phosphoric acid and pk_b of ammonium hydroxide are 5.23 and 4.75 respectively, is ___________.