Choose the weak monobasic acid, among the following

Options

A. `H_(3)BO_(3)`
B. `H_(3)PO_(3)`
C. `H_(3)PO_(4)`
D. `HNO_(3)`

Answer

A

Explanation

`H_(3)BO_(3)` is a weak Lewis monobasic acid, because it can only accept a pair of electron. None of its hydrogen are ionisable.
Note `H_(3)PO_(3)` is a dibasic acid, `H_(3)PO_(4)` is a tribasic acid, `HNO_(3)` is a strong monobasic acid and `H_(4)P_(2)O_(7)` is a tetrabasic acid.