The pH of an aqueous solution of CH₃COONa of concentration C(molarity) is given by

• A

  $7-\frac{1}{2}{\mathrm{pK}}_{\mathrm{a}}-\frac{1}{2}\mathrm{logC}$

• B

  $\frac{1}{2}{\mathrm{pK}}_{\mathrm{w}}-\frac{1}{2}{\mathrm{pK}}_{\mathrm{b}}-\frac{1}{2}\mathrm{logC}$

• C

  $\frac{1}{2}{\mathrm{pK}}_{\mathrm{w}}+\frac{1}{2}{\mathrm{pK}}_{\mathrm{b}}-\frac{1}{2}\mathrm{logC}$

• D

  $\frac{1}{2}{\mathrm{pK}}_{\mathrm{w}}+\frac{1}{2}{\mathrm{pK}}_{\mathrm{a}}+\frac{1}{2}\mathrm{logC}$