Question

H2PO4– + H2O --> H3O+ + HPO4²–
Which of the following is a base–conjugate acid pair?
a)H2O and H3O+
b)H2O and H2PO4–
c)H2PO4– and HPO42–
d)H2PO4– and H3O+

Answer 1

In the reactant side, Hydrogen Phosphate (H2PO4) is an acid while H2O is amphiprotic, meaning it can be a base or acid. Therefore, in this process for the reaction to occur, H2O acts as the base while H3O+ acts as its conjugate acid. The answer is A.

Answer 2

Answer:

H₂O and H₃O⁺

Explanation:

a base is a substance which can accept proton.

When it accept a proton it forms another substance which is called the conjugate acid of the base which has accepted proton.

Here water (H₂O) acts as base as it has accepted proton from H₂PO₄⁻(an acid).

The conjugate acid of H₂O is H₃O⁺, as it has been formed by acceptance of proton by water molecule.