Question

Why is boric acid considered a weak acid?

Answer 1

Weak acids

• Weak acids are acids that do not entirely break down into their constituent ions when dissolved in water.
• When dissolved in water, an equilibrium is created between the concentrations of the weak acid and its constituent ions.

Boric acid is a weak acid

• Boric acid $\left(\mathrm{B}{\left(\mathrm{OH}\right)}_3\right)$ is a monobasic Lewis acid.
• It is an acid composed of four oxygen atoms, one phosphorus atom, and three hydrogen atoms.
• Structure of Boric acid:

• Boric acid is also known as orthoboric acid.
• It is classified as a weak acid since it cannot produce its own hydrogen $\left({\mathrm{H}}^{+}\right)$ ions.
• The boric acid takes hydroxide $\left({\mathrm{OH}}^{-}\right)$ ions from a water molecule and releases ${\mathrm{H}}^{+}$ ions.
• The chemical equation is as follows:

$\mathrm{B}{\left(\mathrm{OH}\right)}_3+{\mathrm{H}}_2\mathrm{O}\to {\left[\mathrm{B}{\left(\mathrm{OH}\right)}_4\right]}^{-}+{\mathrm{H}}^{+}$

• As a result, it is a weak monobasic acid that behaves like a Lewis acid.