Eduprobe
Question:
Three reactions involving H₂PO₄⁻ are given below:
(i) H₃PO₄ + H₂O → H₃O⁺ + H₂PO₄⁻
(ii) H₂PO₄⁻ + H₂O → HPO₄²⁻ + H₃O⁺
(iii) H₂PO₄⁻ + OH⁻ → H₃PO₄ + O²⁻
In which of the above reactions, does H₂PO₄⁻ act as an acid?
(iii) only
(i) and (iii)
(ii) only
(i) and (ii)
Solution:
An acid is one which can accept a pair of e⁻ or donate H⁺. In (ii) only H₂PO₄⁻ acts as an acid by donating H⁺ to water.