Which of the following is the strongest acid ?

Options

A. `H_(3)PO_(4)`
B. `H_(3)PO_(3)`
C. `H_(3)PO_(2)`
D. All are equally strong

Answer

C

Explanation

Care must be excercised compare acids that have similar structures. `H_(3)PO_(2)`, which has two H atoms bonded to the P atom, is a stronger acid than `H_(3)PO_(3)` is a stronger acid than `H_(3)PO_(4)`, which has no H atoms bonded to the P atom.
`H-overset(O)overset(||)underset(H)underset(|)(P)-O-HgtH-overset(O)overset(||)underset(H)underset(|)underset(O)underset(|)(P)-O-HgtH-O-overset(O)overset(||)underset(H)underset(|)underset(O)underset(|)(P)-O-H`