Question

Sodium hydroxide ($\mathrm{NaOH}$) is classified as a strong base. For every mole of Sodium hydroxide added to a large volume of water, one mole of what ion enters the solution?

Answer 1

Dissociation of strong base in aqueous solution:-

1. It is actually a chemical process in which there is basically the breakdown of a smaller substance into the smaller particles such as atoms, ions or molecules.
2. This process occurs with the addition of the solvent as well as the addition of the energy in the form of the heat.
3. In the case of strong bases, they will also dissociate completely in an aqueous solution.
4. Sodium hydroxide ($\mathrm{NaOH}$) is a strong base so it will get dissociated completely in the aqueous solution for the formation of the Sodium cations (${\mathrm{Na}}^{+}$) as well as the Hydroxide ions(${\mathrm{OH}}^{-}$).
5. Reaction:- $\underset{\mathrm{Sodium}\mathrm{hydroxide}}{\mathrm{NaOH}\left(\mathrm{aq}\right)}\to \underset{\mathrm{Sodium}\mathrm{ions}}{{\mathrm{Na}}^{+}\left(\mathrm{aq}\right)}+\underset{\mathrm{Hydroxide}\mathrm{ion}}{{\mathrm{OH}}^{-}\left(\mathrm{aq}\right)}$.
6. One formula unit of the Sodium hydroxide will contain 1 Sodium cation as well as the 1 Hydroxide ion which means that one mole of it will contain one mole of Sodium cations and one mole of the Hydroxide ions.

So, Every mole of the Sodium hydroxide which is dissolved in the solution will produce one mole of the Hydroxide ions which will have the direct impact on the pH of the solution.