`HC-=CHoverset(Dil. H_2SO_4)underset(+Hg^(2+))rarrCH_3CH=0`
Which statement(s) is/are correct about the given reaction?

Options

A. (a) C atom accepting the H is reduced, and the C atom forming a bond with OH is oxidised.
B. (b) Given reaction is a redox reaction.
C. (c) The average oxidation number of the two C atoms in each compound is same `(-1)`.
D. (d) The average oxidation number of the two C atoms in each compound is same `(-2)`. The net effect is no change in average oxidation state.

Answer

To analyze the given reaction and determine which statements are correct, we will break down the reaction step by step.

### Step 1: Identify the Reaction
The reaction given is:
\[ \text{HC≡CH} \overset{\text{Dil. } H_2SO_4}{\underset{+Hg^{2+}}{\rightarrow}} \text{CH}_3\text{CH}_2\text{OH} \]

This indicates that ethyne (HC≡CH) is reacting with dilute sulfuric acid (H₂SO₄) in the presence of mercuric ions (Hg²⁺) to form ethanol (CH₃CH₂OH).

### Step 2: Mechanism of the Reaction
1. **Formation of Vinyl Alcohol**:
- The ethyne undergoes hydration in the presence of H₂SO₄ and Hg²⁺, leading to the formation of vinyl alcohol (CH₂=CHOH).
- This is an initial step where the triple bond is converted to a double bond with the addition of water.

2. **Tautomerization**:
- Vinyl alcohol is unstable and quickly tautomerizes to form ethanol (CH₃CH₂OH).

### Step 3: Oxidation States
To analyze the oxidation states:
- In ethyne (HC≡CH), the carbon atoms are in the -1 oxidation state.
- In ethanol (CH₃CH₂OH), the carbon atoms are in the -1 and 0 oxidation states.

### Step 4: Evaluate Statements
1. **Statement A**: "C atom accepting the H is reduced, C atom forming a bond with OH is oxidized."
- This statement is correct. The carbon that accepts hydrogen (H) is reduced, and the carbon that forms a bond with hydroxyl (OH) is oxidized.

2. **Statement B**: "The given reaction is redox."
- This statement is incorrect. Although there are changes in oxidation states, the overall reaction does not involve a transfer of electrons typical of redox reactions.

3. **Statement C**: "The average oxidation number of the two C atoms in each compound is the same, -1."
- This statement is correct. The average oxidation state of carbon in both the reactant and product remains consistent.

4. **Statement D**: "The average oxidation number of 2 C atoms in each compound is the same, -2, then net effect is no change in average oxidation."
- This statement is incorrect. The average oxidation state changes from -1 in ethyne to -1 and 0 in ethanol.

### Conclusion
The correct statements regarding the reaction are:
- Statement A is correct.
- Statement C is correct.

### Final Answer
The correct statements about the given reaction are A and C.

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