Is NaOH a strong base? | pH of Sodium Hydroxide


NaOH is a strong base(alkali). It dissociate completely to Na+ ion and OH- ion in the water.

NaOH(aq) → Na+(aq) + OH-(aq)

Usually pH values of NaOH solutions are high.

pH values of NaOH solutions

pH values of different concentration(moldm-3) NaOH solutions are shown below at 250C.

  • 0.1 moldm-3 : 13
  • 0.01 moldm-3 : 12
  • 0.001 moldm-3 : 11

We can see, pH value is well above the 7. Therefore we can understand NaOH is a strong base.(alkali)

Na+ ion and OH- ions are stable in the water. Therefore Na+ and OH- ions do not hydrolysis.