Which of the following is a basic oxide ?

Options

A. CaO
B. `CO_(2)`
C. `H_(2)O`
D. `N_(2)O`

Explanation

To determine which of the following is a basic oxide, we need to understand the characteristics of basic oxides and how they behave in water.

### Step-by-Step Solution:

1. **Definition of Basic Oxides**: Basic oxides are oxides that react with water to form hydroxides, which increase the concentration of OH⁻ ions in solution, resulting in a basic (alkaline) solution.

2. **Identifying Metal and Non-Metal Oxides**:
- Metal oxides are generally basic. When they dissolve in water, they produce hydroxides.
- Non-metal oxides are typically acidic. When they dissolve in water, they produce acids.

3. **Analyzing the Options**:
- **Option 1: CaO (Calcium Oxide)**: Calcium is a metal, and CaO is a metal oxide. When CaO is added to water, it reacts to form calcium hydroxide (Ca(OH)₂), which is a strong base. Therefore, CaO is a basic oxide.
- **Option 2: CO₂ (Carbon Dioxide)**: CO₂ is a non-metal oxide. When it dissolves in water, it forms carbonic acid (H₂CO₃), which makes the solution acidic. Thus, CO₂ is not a basic oxide.
- **Option 3: H₂O (Water)**: Water is neutral and does not classify as a basic oxide.
- **Option 4: N₂ (Nitrogen)**: N₂ is a neutral oxide and does not exhibit basic properties.

4. **Conclusion**: Based on the analysis, the only basic oxide among the options provided is **CaO**.

### Final Answer:
**CaO (Calcium Oxide)** is a basic oxide.

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