Question

Consider the reaction below.

H2PO4– + H2O mc030-1.jpg H3O+ + HPO42–

Which of the following is a base–conjugate acid pair?
H2O and H3O+
H2O and H2PO4–
H2PO4– and HPO42–
H2PO4– and H3O+

Answer 1

Answer : The correct option is $H_2O\text{ and }H_3O^+$

Explanation :

According to the Bronsted Lowry concept, Bronsted Lowry-acid is a substance that donates one or more hydrogen ion in a reaction and Bronsted Lowry-base is a substance that accepts one or more hydrogen ion in a reaction.

Or we can say that, conjugate acid is proton donor and conjugate base is proton acceptor.

The given equilibrium reaction will be,

$H_2PO_4^-+H_2O\rightleftharpoons H_3O^++HPO_4^{2-}$

In this reaction, $H_2PO_4^-$ and $H_2O$ are acid and base and $H_3O^+$ and $HPO_4^{2-}$ are conjugate acid and base respectively.

From this we conclude that, $H_2O\text{ and }H_3O^+$ is a base-conjugate acid pair.

Hence, the correct option is $H_2O\text{ and }H_3O^+$

Answer 2

In the given reaction, H₂O and H₃O⁺ is a base-conjugate acid pair.

What is Bronsted-Lowry theory?

It is an acid base theory.

• Acid: a species that donates H⁺.

• Base: a species that accepts H⁺.

If A donates H⁺ to form B, A and B are an acid-base conjugate pair.

Let's consider the following reaction.

H₂PO₄⁻ + H₂O ⇄ H₃O⁺ + HPO₄²⁻

Which of the following is a base-conjugate acid pair?

• H₂O and H₃O⁺. Yes.
• H₂O and H₂PO₄⁻. No, since H₂PO₄⁻ is an acid.
• H₂PO₄⁻ and HPO₄²⁻. No, since H₂PO₄⁻ is an acid and HPO₄²⁻ a base.
• H₂PO₄⁻ and H₃O⁺. No, since both are acids.

In the given reaction, H₂O and H₃O⁺ is a base-conjugate acid pair.

Learn more about base-conjugate acid pair here: https://brainly.com/question/10468518