The nature of CrO and `Cr_2O_3` is respectively

Options

A. Basic, Amphoteric
B. Basic, Basic
C. Amphoteric, Acidic
D. Acidic, Basic

Answer

To determine the nature of CrO (chromium(II) oxide) and Cr2O3 (chromium(III) oxide), we need to analyze the oxidation states of chromium in each compound and their corresponding properties.

### Step-by-Step Solution:

1. **Identify the Oxidation State of Chromium in CrO:**
- In CrO, oxygen has an oxidation state of -2.
- Let the oxidation state of chromium (Cr) be x.
- The overall charge of the compound is neutral (0).
- Therefore, we can set up the equation:
\[ x + (-2) = 0 \]
- Solving for x gives:
\[ x = +2 \]
- Thus, the oxidation state of chromium in CrO is +2.

2. **Identify the Oxidation State of Chromium in Cr2O3:**
- In Cr2O3, oxygen again has an oxidation state of -2.
- Let the oxidation state of chromium be y.
- There are 2 chromium atoms, so the equation becomes:
\[ 2y + 3(-2) = 0 \]
- Simplifying gives:
\[ 2y - 6 = 0 \implies 2y = 6 \implies y = +3 \]
- Thus, the oxidation state of chromium in Cr2O3 is +3.

3. **Determine the Nature of CrO:**
- Compounds with chromium in the +2 oxidation state (like CrO) typically exhibit basic properties.
- Therefore, CrO is **basic**.

4. **Determine the Nature of Cr2O3:**
- Compounds with chromium in the +3 oxidation state (like Cr2O3) can exhibit amphoteric behavior, meaning they can act as both acids and bases.
- Therefore, Cr2O3 is **amphoteric**.

5. **Conclusion:**
- The nature of CrO is basic, and the nature of Cr2O3 is amphoteric.

### Final Answer:
- The nature of CrO and Cr2O3 is respectively **basic and amphoteric**.