Which one is correct for  ${\mathrm{H}}_2\mathrm{O}$ at  ${25}^0\mathrm{C}$

Equilibrium constant for dissociation of water  ${\mathrm{K}}_{\mathrm{c}}=1.8\times {10}^{-16}$

Ionic product of water  ${\mathrm{K}}_{\mathrm{w}}=\left[{\mathrm{H}}^{+}\right]\left[{\mathrm{OH}}^{-}\right]={10}^{-7}\times {10}^{-7}={10}^{-14}$

Also, as we increase temperature, more no of ions will be produced and concentration of hydrogen ions as well as hydroxide ions will be increase and K_w increases.

Autoprotolysis constant of water  ${\mathrm{K}}_{\mathrm{AP}}=3.2\times {10}^{-18}$.