Incorrect statement among the following is :

Options

A. Oxidation state of chromium in chromate and dichomate is same
B. Oxidation of manganese is different in manganate and permanganate
C. Colour of chromate and dichromate is orange
D. Chromate ion gets converted into dichromate ion in acidic medium

Answer

To solve the question, we need to analyze each statement provided and determine which one is incorrect.

### Step-by-Step Solution:

1. **Statement 1: Oxidation state of chromium in chromate and dichromate is the same.**
- **Chromate Ion (CrO4²⁻)**:
- Let the oxidation state of Cr be \( x \).
- The equation is: \( x + 4(-2) = -2 \)
- This simplifies to: \( x - 8 = -2 \)
- Therefore, \( x = +6 \).
- **Dichromate Ion (Cr2O7²⁻)**:
- Let the oxidation state of Cr be \( x \).
- The equation is: \( 2x + 7(-2) = -2 \)
- This simplifies to: \( 2x - 14 = -2 \)
- Therefore, \( 2x = 12 \) and \( x = +6 \).
- **Conclusion**: The oxidation state of chromium in both chromate and dichromate is +6. This statement is **true**.

2. **Statement 2: Oxidation state of manganese is different in manganate and permanganate.**
- **Manganate Ion (MnO4²⁻)**:
- Let the oxidation state of Mn be \( x \).
- The equation is: \( x + 4(-2) = -2 \)
- This simplifies to: \( x - 8 = -2 \)
- Therefore, \( x = +6 \).
- **Permanganate Ion (MnO4⁻)**:
- Let the oxidation state of Mn be \( x \).
- The equation is: \( x + 4(-2) = -1 \)
- This simplifies to: \( x - 8 = -1 \)
- Therefore, \( x = +7 \).
- **Conclusion**: The oxidation state of manganese is +6 in manganate and +7 in permanganate. This statement is **true**.

3. **Statement 3: Color of chromate and dichromate is orange.**
- **Chromate Ion**: The color of chromate (CrO4²⁻) is **yellow**.
- **Dichromate Ion**: The color of dichromate (Cr2O7²⁻) is **orange**.
- **Conclusion**: This statement is **incorrect** because it incorrectly states that both colors are orange.

4. **Statement 4: Chromate ion gets converted to dichromate ion in acidic medium.**
- The reaction is:
\[ \text{CrO4}^{2-} + 2\text{H}^+ \rightarrow \text{Cr2O7}^{2-} + \text{H2O} \]
- **Conclusion**: This statement is **true**.

### Final Answer:
The incorrect statement among the options is: **Color of chromate and dichromate is orange.**