The ionisation of weak base M OH can be represented by equation,

$\mathrm{MOH}\left(\mathrm{aq}\right)\rightleftharpoons {\mathrm{M}}^{+}\left(\mathrm{aq}\right)+{\mathrm{OH}}^{-}\left(\mathrm{aq}\right)$

                          ${\mathrm{K}}_{\mathrm{b}}=\left[{\mathrm{M}}^{+}\right]\left[{\mathrm{OH}}^{-}\right]/\left[\mathrm{MOH}\right]$

where, ${\mathrm{K}}_{\mathrm{b}}$ is represented as

 

• A

  acidic ionisation constant

• B

  basic ionisation constant

• C

  ionic product of water

• D

  Both (a) and (b)