What is the conjugate acid of HCO3-?
The correct answer and explanation is:
The conjugate acid of HCO3⁻ (bicarbonate ion) is H2CO3 (carbonic acid).
Explanation:
In acid-base chemistry, a conjugate acid is formed when a base gains a proton (H⁺). The bicarbonate ion, HCO3⁻, can act as a base by accepting a proton. When HCO3⁻ accepts a proton, it forms H2CO3.
The reaction can be written as:
HCO3⁻ + H⁺ → H2CO3
Here, bicarbonate (HCO3⁻) acts as a base and accepts a hydrogen ion (proton), resulting in carbonic acid (H2CO3), which is the conjugate acid of bicarbonate.
This relationship is important in the bicarbonate buffer system, which helps maintain the pH balance in blood and other bodily fluids. The bicarbonate ion can either accept a proton to form carbonic acid or donate a proton to form carbonate ion (CO3²⁻), depending on the pH of the environment.
To summarize the key points:
- A conjugate acid forms when a base gains a proton.
- HCO3⁻ is a base that can accept a proton.
- When HCO3⁻ accepts a proton, it forms H2CO3.
- Therefore, the conjugate acid of bicarbonate ion is carbonic acid (H2CO3).
Understanding conjugate acid-base pairs is essential in many chemical and biological systems because it explains how substances behave in acid-base reactions and helps predict the direction of these reactions.