Q.Is boric acid a protic acid? Explain.

Step 1 - What a protic (Bronsted) acid is

A protic acid is one that directly donates a proton ($H^+$) from one of its own O-H bonds by simple ionisation, e.g. $\text{CH}_3\text{COOH} \rightleftharpoons \text{CH}_3\text{COO}^- + \text{H}^+$.

Step 2 - How boric acid actually behaves

Boric acid, $\text{B(OH)}_3$, has boron with an incomplete octet ($sp^2$, empty $2p$ orbital) - it is a Lewis acid (electron-pair acceptor), not a proton donor. It reacts with water by accepting a lone pair (effectively $\text{OH}^-$) from a water molecule:

Step 3 - The proton comes from water, not boric acid …

Distinguish a Bronsted/protic acid (donates its own H+ by direct ionisation) from a Lewis acid (accepts an electron pair). Show boric acid's equilibrium with water - the proton come …

• Calling boric acid a protic acid simply because it produces H+ in solution - the mechanism (Lewis acid-base with water) matters, not just the net effect.
• Miscounting it as tribasic (releasing 3 H+ from its 3 OH groups) instead of monobasic. …