A weak acid is titrated with a weak base. Consider the following statements regarding the $\mathrm{pH}$ of the solution at the equivalence point:

(i) $\mathrm{pH}$ depends on the concentration of acid and base.

(ii) $\mathrm{pH}$ is independent of the concentration of acid and base

(iii) $\mathrm{pH}$ depends on the ${\mathrm{pK}}_{\mathrm{a}}$ of acid and ${\mathrm{pK}}_{\mathrm{b}}$ of base.

(iv) $\mathrm{pH}$ is independent of the ${\mathrm{pK}}_{\mathrm{a}}$ of acid and ${\mathrm{pK}}_{\mathrm{b}}$ of base.

The correct statements are:-