`CrO_(3)` is `a//an"….."`

Options

A. acidic oxide
B. basic oxide
C. neutral oxide
D. Amphoteric oxide

Answer

To determine the nature of CrO₃ (chromium trioxide), we will follow these steps:

### Step 1: Determine the oxidation state of chromium in CrO₃.
- Let the oxidation state of chromium be \( X \).
- Each oxygen atom has an oxidation state of -2, and there are 3 oxygen atoms.
- The overall charge of the molecule is 0.

**Equation:**
\[ X + 3(-2) = 0 \]
\[ X - 6 = 0 \]
\[ X = +6 \]

### Step 2: Analyze the oxidation state.
- The oxidation state of chromium in CrO₃ is +6. This is a high oxidation state.

### Step 3: Determine the acidic or basic nature of the oxide.
- Oxides of metals in high oxidation states tend to be acidic.
- Chromium in the +6 state is highly electronegative and has a strong tendency to accept electrons.

### Step 4: Identify the behavior of CrO₃ with water.
- When CrO₃ reacts with water, it forms chromic acid (H₂CrO₄).

**Reaction:**
\[ \text{CrO}_3 + \text{H}_2\text{O} \rightarrow \text{H}_2\text{CrO}_4 \]

### Step 5: Conclude the nature of CrO₃.
- Since CrO₃ can react with water to form an acid and behaves as a Lewis acid, it is classified as an acidic oxide.

### Final Answer:
CrO₃ is an **acidic oxide**.

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