Which of the following does not turn Schiff's reagent to pink?

Options

A. Formaldehye
B. Propanaldehyde
C. Acetone
D. Acetaldehyde

Answer

To solve the question of which compound does not turn Schiff's reagent to pink, we can follow these steps:

### Step 1: Understand Schiff's Reagent
Schiff's reagent is a chemical test used to detect the presence of aldehydes. It is formed from a dye (like fuchsin) and sodium bisulfite. When aldehydes react with Schiff's reagent, they produce a pink color.

**Hint:** Remember that Schiff's reagent is specifically sensitive to aldehydes, not ketones.

### Step 2: Identify the Compounds
The question provides several options. We need to analyze each compound to determine if it is an aldehyde or a ketone:
- **Formaldehyde (HCHO)**: This is an aldehyde.
- **Propionaldehyde (C2H5CHO)**: This is also an aldehyde.
- **Acetone (CH3COCH3)**: This is a ketone.
- **Acetaldehyde (CH3CHO)**: This is an aldehyde.

**Hint:** Classify each compound as either an aldehyde or a ketone.

### Step 3: Analyze the Reaction with Schiff's Reagent
- **Formaldehyde**: Reacts with Schiff's reagent and turns it pink.
- **Propionaldehyde**: Also reacts with Schiff's reagent and turns it pink.
- **Acetone**: Does not react with Schiff's reagent because it is a ketone, so it does not turn the reagent pink.
- **Acetaldehyde**: Reacts with Schiff's reagent and turns it pink.

**Hint:** Only aldehydes will cause a color change with Schiff's reagent.

### Step 4: Conclusion
From the analysis, we conclude that **acetone** is the only compound that does not turn Schiff's reagent to pink, as it is a ketone and does not react with the reagent.

**Final Answer:** Acetone does not turn Schiff's reagent to pink.