Identify the correct order of acidic strength of `CO_(2),CuO, CaO` and `H_(2)O`.

Options

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

Explanation

To determine the correct order of acidic strength of \( CO_2, CuO, CaO, \) and \( H_2O \), we can analyze the acidic properties of these compounds based on their chemical nature.

### Step-by-Step Solution:

1. **Identify the Nature of Each Compound**:
- \( CO_2 \) (Carbon Dioxide): A non-metallic oxide that is acidic in nature.
- \( CuO \) (Copper(II) Oxide): A basic oxide, typically less acidic.
- \( CaO \) (Calcium Oxide): An alkaline earth metal oxide, which is also basic.
- \( H_2O \) (Water): Neutral in nature, but can act as a very weak acid.

2. **Determine the Acidic Strength**:
- Non-metallic oxides like \( CO_2 \) tend to be more acidic because they can react with water to form acids (e.g., \( CO_2 + H_2O \rightarrow H_2CO_3 \)).
- Basic oxides like \( CuO \) and \( CaO \) do not produce acidic solutions; \( CaO \) is less acidic than \( CO_2 \).
- Water is neutral but can slightly dissociate to produce \( H^+ \) ions, making it a very weak acid.

3. **Rank the Compounds**:
- Since \( CO_2 \) produces an acid when dissolved in water, it is more acidic than \( H_2O \).
- Between \( CaO \) and \( CuO \), both are basic, but \( CaO \) is more basic than \( CuO \) because it is an alkaline earth metal oxide.
- Therefore, the order of acidic strength from strongest to weakest is:
\[ CO_2 > H_2O > CuO > CaO \]

4. **Final Order**:
- The correct order of acidic strength is:
\[ CO_2 > H_2O > CuO > CaO \]

### Conclusion:
The correct order of acidic strength is \( CO_2 > H_2O > CuO > CaO \).