How will you bring about following conversions?i.Acetic acid to acetyl chlorideII.Methyl cyanide to acetic acidiii..Acetyl chloride to ethyl acetateiv.Ethyl iodide to ethyl acetate

To achieve the conversions listed in your question, we will use specific organic reactions and reagents. Let’s go through each conversion step by step.

### i. Acetic acid to acetyl chloride

**Conversion Reaction:**
Acetic acid (CH₃COOH) can be converted to acetyl chloride (CH₃COCl) using thionyl chloride (SOCl₂) or oxalyl chloride (COCl)₂.

**Reaction:**
\[
\text{CH}_3\text{COOH} + \text{SOCl}_2 \rightarrow \text{CH}_3\text{COCl} + \text{SO}_2 + \text{HCl}
\]

**Explanation:**
1. **Thionyl Chloride (SOCl₂)** reacts with acetic acid, replacing the hydroxyl group (-OH) with a chlorine atom (-Cl).
2. The by-products are sulfur dioxide (SO₂) and hydrochloric acid (HCl), which can easily be removed from the reaction mixture.

### ii. Methyl cyanide to acetic acid

**Conversion Reaction:**
Methyl cyanide (or acetonitrile, CH₃CN) can be hydrolyzed to form acetic acid.

**Reaction:**
\[
\text{CH}_3\text{CN} + 2 \text{H}_2\text{O} \rightarrow \text{CH}_3\text{COOH} + \text{NH}_3
\]

**Explanation:**
1. The nitrile group (-C≡N) undergoes hydrolysis in the presence of water.
2. This reaction can be catalyzed by an acid or a base, leading to the formation of acetic acid and ammonia (NH₃).

### iii. Acetyl chloride to ethyl acetate

**Conversion Reaction:**
Acetyl chloride can be converted to ethyl acetate (CH₃COOCH₂CH₃) through a reaction with ethanol (C₂H₅OH).

**Reaction:**
\[
\text{CH}_3\text{COCl} + \text{C}_2\text{H}_5\text{OH} \rightarrow \text{CH}_3\text{COOCH}_2\text{CH}_3 + \text{HCl}
\]

**Explanation:**
1. The acetyl chloride reacts with ethanol in a nucleophilic substitution reaction.
2. The hydroxyl group from ethanol attacks the carbonyl carbon of the acetyl chloride, resulting in the formation of ethyl acetate and hydrochloric acid (HCl) as a by-product.

### iv. Ethyl iodide to ethyl acetate

**Conversion Reaction:**
Ethyl iodide (C₂H₅I) can be converted to ethyl acetate using sodium acetate (CH₃COONa) through an S_N2 reaction.

**Reaction:**
\[
\text{C}_2\text{H}_5\text{I} + \text{CH}_3\text{COONa} \rightarrow \text{CH}_3\text{COOC}_2\text{H}_5 + \text{NaI}
\]

**Explanation:**
1. The ethyl iodide undergoes nucleophilic substitution where the iodide ion (I⁻) is replaced by the acetate ion (CH₃COO⁻) from sodium acetate.
2. This reaction results in the formation of ethyl acetate and sodium iodide (NaI).

### Summary of Conversions:
1. **Acetic acid to acetyl chloride**: Use thionyl chloride (SOCl₂).
2. **Methyl cyanide to acetic acid**: Hydrolyze with water.
3. **Acetyl chloride to ethyl acetate**: React with ethanol.
4. **Ethyl iodide to ethyl acetate**: Use sodium acetate for nucleophilic substitution.

This covers the conversions you requested with detailed steps and explanations! If you have further questions or need clarification, feel free to ask.