Question

Which of the following is a conjugate acid-base pair in the reaction represented by the

Answer 1

Answer:  $H_2PO_4$ and $H_3PO_4$

Explanation:

According to the Bronsted-Lowry conjugate acid-base theory, an acid is defined as a substance which looses donates protons and thus forming conjugate base and a base is defined as a substance which accepts protons and thus forming conjugate acid.

For the given reaction:

$H_2PO_4^-+H_2O\rightleftharpoons H_3PO_4+OH^-$

Here, $H_2O$ is loosing a proton, thus it is considered as an acid and after losing a proton, it forms $OH^-$ which is a conjugate base.

Similarly , $H_2PO_4^-$ is gaining a proton, thus it is considered as an base and after gaining a proton, it forms $H_3PO_4$ which is a conjugate acid.

Thus $H_2PO_4$ and $H_3PO_4$ is a conjugate acid-base pair in the reaction represented by the equation below