Which of the following is correct for finding out the ${\mathrm{P}}^{\mathrm{H}}$of a buffer?

• A

  ${\mathrm{P}}^{\mathrm{H}}={\mathrm{P}}^{{\mathrm{K}}_{\mathrm{a}}}+\log \frac{\left[\mathrm{salt}\right]}{\left[\mathrm{acid}\right]}$

• B

  ${\mathrm{P}}^{\mathrm{OH}}={\mathrm{P}}^{{\mathrm{K}}_{\mathrm{b}}}+\log \frac{\left[\mathrm{salt}\right]}{\left[\mathrm{base}\right]}$ followed by ${\mathrm{P}}^{\mathrm{H}}=14-{\mathrm{P}}^{\mathrm{OH}}$

• C

  ${\mathrm{P}}^{\mathrm{H}}={\mathrm{P}}^{{\mathrm{K}}_{\mathrm{a}}}+\log \frac{\left[\mathrm{salt} \mathrm{of} \mathrm{conjugate} \mathrm{base}\right]}{\left[\mathrm{weak} \mathrm{acid}\right]}$

• D

  All of the above