In the dissociation of bicarbonate ion, the conjugate base involved is :

Options

A. `CO_(3)^(2-)`
B. `CO_(2)`
C. `H_(2)CO_(3)`
D. CO

Explanation

To determine the conjugate base involved in the dissociation of the bicarbonate ion (HCO3⁻), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Bicarbonate Ion**:
The bicarbonate ion is represented as HCO3⁻. It can act as an acid by donating a proton (H⁺).

2. **Dissociation of Bicarbonate Ion**:
When the bicarbonate ion dissociates, it donates a proton (H⁺) to form another species. The dissociation reaction can be written as:
\[ \text{HCO}_3^- \rightarrow \text{CO}_3^{2-} + \text{H}^+ \]

3. **Identify the Conjugate Base**:
The species that remains after the bicarbonate ion donates a proton is the carbonate ion (CO3²⁻). This species is known as the conjugate base of bicarbonate.

4. **Conclusion**:
Therefore, the conjugate base involved in the dissociation of the bicarbonate ion (HCO3⁻) is the carbonate ion (CO3²⁻).

### Final Answer:
The conjugate base involved in the dissociation of bicarbonate ion is **carbonate ion (CO3²⁻)**.

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