Select the correct statement(s).

If $\left[{\mathrm{H}}^{+}\right]$concentration is decreased 100 times, pH of solution increases by 2 units.

If solution of ${\mathrm{CH}}_3\mathrm{COONa}$(aq) is diluted then pH increases.

If pOH of aq. solution at 70° C is 7, then solution will be acidic.

Buffer capacity remains constant with dilution.