Which of the following is not an example of redox reaction?

Options

A. `CuO+H_(2)rarrCu+H_(2)O`
B. `Fe_(2)O_(3)+3CO rarr 2Fe + 3 CO_(2)`
C. `2K+F_(2) rarr 2KF`
D. `BaCl_(2)+H_(2)SO_(4) rarr BaSO_(4)+2HCl`

Explanation

To determine which of the given reactions is not an example of a redox reaction, we need to analyze the oxidation states of the elements involved in each reaction. A redox reaction involves the transfer of electrons, resulting in changes in oxidation states (oxidation and reduction).

Let's analyze each option step by step:

### Step 1: Identify the Reactions
We have the following reactions to analyze:
1. Cu^2+ + H2 → Cu + 2H^+
2. Fe2O3 + 3CO → 2Fe + 3CO2
3. BaCl2 + H2SO4 → BaSO4 + 2HCl
4. 2K + F2 → 2KF

### Step 2: Analyze Each Reaction
1. **Cu^2+ + H2 → Cu + 2H^+**
- Oxidation states: Cu changes from +2 to 0 (reduction), H2 changes from 0 to +1 (oxidation).
- This is a redox reaction.

2. **Fe2O3 + 3CO → 2Fe + 3CO2**
- Oxidation states: Fe changes from +3 to 0 (reduction), C changes from +2 in CO to +4 in CO2 (oxidation).
- This is a redox reaction.

3. **BaCl2 + H2SO4 → BaSO4 + 2HCl**
- Oxidation states: Ba remains +2, Cl remains -1, S remains +6, and O remains -2. There are no changes in oxidation states.
- This is **not** a redox reaction.

4. **2K + F2 → 2KF**
- Oxidation states: K changes from 0 to +1 (oxidation), F changes from 0 to -1 (reduction).
- This is a redox reaction.

### Step 3: Conclusion
After analyzing all the reactions, we find that the reaction **BaCl2 + H2SO4 → BaSO4 + 2HCl** does not involve any change in oxidation states, and therefore, it is not an example of a redox reaction.

**Answer: BaCl2 + H2SO4 → BaSO4 + 2HCl (Option 3)**

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