Identify the correct order of acidic strengths of `CO_(2) , CuO , CaO , H_(2)O` :

Options

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

Answer

To determine the correct order of acidic strengths of the compounds CO₂, CuO, CaO, and H₂O, we need to analyze the nature of each compound based on their metallic or non-metallic character.

### Step-by-Step Solution:

1. **Identify the Nature of Each Compound**:
- **CO₂ (Carbon Dioxide)**: This is a non-metal oxide. Non-metal oxides are generally acidic.
- **CuO (Copper(II) Oxide)**: This is a metal oxide. Metal oxides are typically basic.
- **CaO (Calcium Oxide)**: This is also a metal oxide and is very basic.
- **H₂O (Water)**: This is a non-metal oxide and can exhibit both acidic and basic properties, but is generally considered neutral.

2. **Rank the Compounds Based on Acidic Strength**:
- Non-metal oxides like CO₂ are more acidic compared to metal oxides.
- Between the metal oxides, the one with the higher metallic character will be less acidic.
- **Comparison**:
- CO₂ is acidic.
- H₂O is less acidic than CO₂ but more acidic than metal oxides.
- CuO is less acidic than H₂O because it is a metal oxide.
- CaO is the least acidic among the four since it is a strong basic oxide.

3. **Final Order of Acidic Strength**:
- The order of acidic strengths from strongest to weakest is:
- CO₂ > H₂O > CuO > CaO

### Conclusion:
The correct order of acidic strengths of the compounds is:
**CO₂ > H₂O > CuO > CaO**