Which is the major product formed when acetone is heated with iodine and potassium hydroxide ?

Options

A. Acetophenone
B. Iodoform
C. lodoacetone
D. Acetic acid

Answer

To determine the major product formed when acetone is heated with iodine and potassium hydroxide, we can follow these steps:

### Step 1: Identify the Reaction Type
The reaction between acetone, iodine, and potassium hydroxide is known as the haloform reaction. This reaction is characteristic of methyl ketones, where a ketone undergoes halogenation in the presence of a base.

**Hint:** Look for reactions involving halogens and ketones, particularly with methyl ketones.

### Step 2: Write the Structure of Acetone
Acetone is a simple ketone with the molecular formula \( \text{C}_3\text{H}_6\text{O} \). Its structure can be represented as:
\[ \text{CH}_3\text{COCH}_3 \]

**Hint:** Remember that acetone has a carbonyl group (C=O) flanked by two methyl groups.

### Step 3: Reaction with Iodine and Potassium Hydroxide
In the presence of iodine (I2) and potassium hydroxide (KOH), acetone will undergo halogenation. The base (KOH) will deprotonate the acetone, allowing iodine to react with the methyl group adjacent to the carbonyl.

**Hint:** Focus on the role of the base in facilitating the reaction.

### Step 4: Formation of Iodoform
During the reaction, the methyl group of acetone will be halogenated, leading to the formation of iodoform (CHI3) as a byproduct. The remaining part of the molecule will convert into a carboxylate ion (potassium acetate).

The overall reaction can be summarized as:
\[ \text{CH}_3\text{COCH}_3 + 3 \text{I}_2 + 4 \text{KOH} \rightarrow \text{CH}_3\text{COOK} + 3 \text{CHI}_3 + 3 \text{H}_2\text{O} \]

**Hint:** Remember that iodoform is a yellow precipitate that indicates the presence of a methyl ketone.

### Step 5: Identify the Major Product
The major product formed from this reaction is iodoform (CHI3), which is a yellow precipitate. The other product is potassium acetate (CH3COOK).

**Hint:** The presence of a yellow precipitate is a key indicator of the reaction's success.

### Conclusion
The major product formed when acetone is heated with iodine and potassium hydroxide is iodoform (CHI3).

**Final Answer:** Iodoform (CHI3)