Which of the following is incorrect statement?

If ${\mathrm{K}}_1$ and ${\mathrm{K}}_2$for dissociation of ${\mathrm{H}}_2$A is ${10}^{- 7}$ and ${10}^{-14}$ then A 2 - concentration in 0.1 M ${\mathrm{H}}_2$ A solution is ${10}^{- 7}$

pH of acidic buffer solution depends upon ${\mathrm{pK}}_{\mathrm{a}}$ and relative molar amount of weak acid and its conjugate base.

If a salt solution of weak acid and weak base is diluted up to limited extent then its pH will decrease

A solution of pH= 1 has ${\mathrm{H}}^{+}$ ion concentration 3 times that of a solution of pH = 3