The species presents in the solution when `CO_(2)` is dissolves in water are

Options

A. `CO_(2),H_(2)CO_(3),HCO_(3)^(Θ),CO_(3)^(2-)`
B. `H_(2)CO_(3),CO_(3)^(2-)`
C. `CO_(3)^(2-),HCO_(3)^(Θ)`
D. `CO_(2),H_(2)CO_(3)`

Explanation

To determine the species present in the solution when carbon dioxide (CO₂) is dissolved in water, we can follow these steps:

### Step-by-Step Solution:

1. **Dissolution of CO₂ in Water**:
When carbon dioxide gas is dissolved in water, it reacts to form carbonic acid (H₂CO₃). The reaction can be represented as:
\[ \text{CO}_2 (g) + \text{H}_2\text{O} (l) \rightarrow \text{H}_2\text{CO}_3 (aq) \]

2. **Formation of Carbonic Acid**:
The carbonic acid formed is a weak acid and can partially ionize in water. The ionization of carbonic acid can be represented as:
\[ \text{H}_2\text{CO}_3 (aq) \rightleftharpoons \text{H}^+ (aq) + \text{HCO}_3^- (aq) \]
Here, HCO₃⁻ is the bicarbonate ion (or hydrogen carbonate ion).

3. **Further Ionization of Bicarbonate Ion**:
The bicarbonate ion can further ionize to produce carbonate ions (CO₃²⁻):
\[ \text{HCO}_3^- (aq) \rightleftharpoons \text{H}^+ (aq) + \text{CO}_3^{2-} (aq) \]

4. **Species Present in the Solution**:
Therefore, the species present in the solution when CO₂ is dissolved in water are:
- Carbon dioxide (CO₂)
- Carbonic acid (H₂CO₃)
- Bicarbonate ion (HCO₃⁻)
- Carbonate ion (CO₃²⁻)

### Conclusion:
The complete list of species present in the solution is:
- CO₂
- H₂CO₃
- HCO₃⁻
- CO₃²⁻