Question

How is the concentration of hydronium ions affected when a solution of an acid is diluted?

Answer 1

Acid:-

• A substance that has the capability to donate a proton that is a hydrogen ion to other substances is called an Acid.
• This acidic strength depends on the concentration of hydronium ions.
• The more the substance releases hydronium ions, the more acidic it is.
• Some examples of acid are, Sulphuric acid$\left({\mathrm{H}}_2{\mathrm{SO}}_4\right)$, Hydrochloric acid$\left(\mathrm{HCl}\right)$

Effect of dilution on the concentration of Hydronium ions:-

• When an acid is dissolved in water, it ionizes and produces hydronium ions$\left({\mathrm{H}}_3{\mathrm{O}}^{+}\right)$.
• When water is added, the hydroxyl ions$\left({\mathrm{OH}}^{-}\right)$from the water and the hydronium ion$\left({\mathrm{H}}_3{\mathrm{O}}^{+}\right)$ from the acid reacts and forms water molecules.
• Hence the solution gets more and more diluted.
• As a result of this, the concentration of hydronium ion decreases, and thus the strength of the acid also decreases.

Therefore, the concentration of hydronium ions in an acid decrease when it is diluted.