Phosphorus forms a number of oxoacids which differ in their structures and oxidation state of phosphorus. All the acids contain phosphorus atom//atoms linked tetrahedrally to four other atoms or groups. Each of them has at least one `P=O` or `P rarr O` unit and one `P-OH` unit. The `OH` group is ionisable but `H` atom linked directly to `P` is non-ionisabl. Structures of all the acids are considered to be derived either from phosphorus acid or phosphoric acid. Which one is monobasic acid ?A. `H_3 PO_2`B. `H_3 PO_3`C. `H_3 PO_4`D. `H_3 PO_5`

Phosphorus forms a number of oxoacids which differ in their structures

1.	Phosphorus forms a number of oxoacids which differ in their structures and oxidation state of phosphorus. All the acids contain phosphorus atom//atoms linked tetrahedrally to four other atoms or groups. Each of them has at least one `P=O` or `P rarr O` unit and one `P-OH` unit. The `OH` group is ionisable but `H` atom linked directly to `P` is non-ionisabl. Structures of all the acids are considered to be derived either from phosphorus acid or phosphoric acid. Which one is monobasic acid ?A. `H_3 PO_2`B. `H_3 PO_3`C. `H_3 PO_4`D. `H_3 PO_5`
Answer» Correct Answer - A `H_3 PO_2` contains one `P-OH` group.