In the following equation, identify the acids, bases, and conjugate pairs. NH4 + + BrO3 ? ? NH3 + HBrO3 (a) What is the acid? (b) What is its conjugate base? (c) What is the base? d) What is its conjugate acid?
The Correct Answer and Explanation is:
Let’s break down the given equation:
NH₄⁺ + BrO₃⁻ ⇌ NH₃ + HBrO₃
This is a typical acid-base reaction in water, and it follows the Bronsted-Lowry acid-base theory. According to this theory:
- An acid is a proton (H⁺) donor.
- A base is a proton (H⁺) acceptor.
- Conjugate acid is what the base becomes after accepting a proton.
- Conjugate base is what the acid becomes after donating a proton.
Now, let’s analyze each part of the equation:
(a) What is the acid?
The acid is NH₄⁺ (ammonium ion).
Why? NH₄⁺ donates a proton (H⁺) to become NH₃ (ammonia). The proton is transferred from NH₄⁺ to BrO₃⁻, which makes NH₄⁺ the acid.
(b) What is its conjugate base?
The conjugate base of NH₄⁺ is NH₃ (ammonia).
When NH₄⁺ donates a proton (H⁺), it becomes NH₃, which is its conjugate base. In essence, NH₃ is the species that results after NH₄⁺ has given up its proton.
(c) What is the base?
The base in this reaction is BrO₃⁻ (bromate ion).
Why? BrO₃⁻ accepts a proton (H⁺) to become HBrO₃ (bromous acid). Therefore, BrO₃⁻ is the base since it takes in a proton.
(d) What is its conjugate acid?
The conjugate acid of BrO₃⁻ is HBrO₃ (bromous acid).
Once BrO₃⁻ accepts a proton, it becomes HBrO₃, which is its conjugate acid. The species formed after the base accepts a proton is always its conjugate acid.
Summary:
- (a) The acid is NH₄⁺.
- (b) Its conjugate base is NH₃.
- (c) The base is BrO₃⁻.
- (d) Its conjugate acid is HBrO₃.
This reaction demonstrates how acids and bases interact through proton transfer, resulting in conjugate acid-base pairs.
