Which of the following oxide is acidic in nature ?

Options

A. `CrO `
B. `Cr_(2)O_(3)`
C. `CrO_(3)`
D. `CrO_(2)`

Answer

To determine which of the following chromium oxides is acidic in nature, we need to analyze the oxidation states of chromium in each oxide and their corresponding acidic or basic character.

### Step-by-Step Solution:

1. **Identify the Oxides**: The oxides given are:
- CrO
- Cr2O3
- CrO3
- CrO2

2. **Determine the Oxidation State of Chromium**:
- For each oxide, we will set up an equation based on the known oxidation state of oxygen, which is -2.

**For CrO**:
- Let the oxidation state of Cr be \( x \).
- The equation is:
\[ x + (-2) = 0 \implies x = +2 \]

**For Cr2O3**:
- Let the oxidation state of Cr be \( x \).
- The equation is:
\[ 2x + 3(-2) = 0 \implies 2x - 6 = 0 \implies 2x = 6 \implies x = +3 \]

**For CrO3**:
- Let the oxidation state of Cr be \( x \).
- The equation is:
\[ x + 3(-2) = 0 \implies x - 6 = 0 \implies x = +6 \]

**For CrO2**:
- Let the oxidation state of Cr be \( x \).
- The equation is:
\[ x + 2(-2) = 0 \implies x - 4 = 0 \implies x = +4 \]

3. **Summarize the Oxidation States**:
- CrO: +2
- Cr2O3: +3
- CrO3: +6
- CrO2: +4

4. **Determine Acidic or Basic Nature**:
- Generally, the acidic character of oxides increases with the oxidation state of the metal. Higher oxidation states typically correspond to more acidic oxides.
- Among the calculated oxidation states, CrO3 has the highest oxidation state of +6.

5. **Conclusion**:
- Therefore, CrO3 is the oxide that is acidic in nature.

### Final Answer:
**CrO3 is acidic in nature.**

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