Q62 / 200 · NEET 2003 · Chemistry
Which one of the following compounds is not a protonic acid?
- Correct answerA$\mathrm{B}(\mathrm{OH})_3$
- B$\mathrm{PO}(\mathrm{OH})_3$
- C$\mathrm{SO}(\mathrm{OH})_2$
- D$\mathrm{SO}_2(\mathrm{OH})_1$
Solution
Boric acid is not a protic acid. Boric acid is a weak monobasic acid. It is not a protonic acid but acts as a Lewis acid by accepting electrons from a hydroxyl ion and in turn releases $\mathrm{H}^{+}$ ions
Related Theory Although Boric acid contains $3 \mathrm{OH}$ groups yet it can act as monobasic acid rather than tribasic acid, since, only one $\mathrm{H}^{+}$can be released by a water molecule.
Related Theory Although Boric acid contains $3 \mathrm{OH}$ groups yet it can act as monobasic acid rather than tribasic acid, since, only one $\mathrm{H}^{+}$can be released by a water molecule.
Hence, the correct answer is option: 'A'.