Which of the following statement is wrong?

Options

A. In highest oxidation states, the transition metals show acidic character.
B. `Mn^(3+)` and `Co^(3+)` are oxidising agents in aqueous solution.
C. Metals in highest oxidation states are more stable in oxides than in fluorides.
D. All elements of 3d series exhibit variable oxidation states.

Explanation

To determine which statement is wrong among the given options regarding transition metals and their properties, we will analyze each statement step by step.

### Step 1: Analyze the first statement
**Statement A:** In the highest oxidation state, the transition metal shows acidic character.

- **Explanation:** This statement is correct. As the oxidation state of transition metals increases, their acidic character also increases. For example, Mn2O7 and Cr2O5 are known to be acidic oxides due to their high oxidation states.

### Step 2: Analyze the second statement
**Statement B:** Mn3+ and Co3+ are oxidizing agents in aqueous solution.

- **Explanation:** This statement is also correct. Mn3+ can be reduced to Mn2+, and since it undergoes reduction, it acts as an oxidizing agent. Similarly, Co3+ can be reduced to Co2+, making it an oxidizing agent as well.

### Step 3: Analyze the third statement
**Statement C:** Metals in the highest oxidation state are more stable in oxides than in fluorides.

- **Explanation:** This statement is correct. For example, Mn2O7 is more stable than MnF7 in the +7 oxidation state due to steric hindrance. The presence of multiple fluorine atoms creates instability compared to the oxide.

### Step 4: Analyze the fourth statement
**Statement D:** Zinc has a variable oxidation state.

- **Explanation:** This statement is incorrect. Zinc typically exhibits a +2 oxidation state and does not show variable oxidation states like other transition metals. Therefore, this statement is the wrong one among the options.

### Conclusion
After analyzing all the statements, we find that **Statement D** is wrong.

### Final Answer
The answer is **D**: Zinc has a variable oxidation state (this statement is wrong).

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