Which of the following statement is false ?

Options

A. Cannizzaro reaction is given by aldehydes in presence of alkali
B. Aldol condensation is given by aldehydes in presence of alkali
C. Aldol condensation is given by aldehydes and ketones in presence of acids
D. None

Answer

To determine which of the statements is false, we need to analyze each statement carefully. Here’s a step-by-step breakdown of the solution:

### Step 1: Analyze the Statements
We are given three statements regarding chemical reactions involving aldehydes and ketones. We need to identify any false statement among them.

### Step 2: Understand Aldol Condensation
Aldol condensation occurs when aldehydes or ketones with at least one alpha hydrogen react in the presence of a base (like NaOH or KOH). The product formed is known as an aldol, which contains both aldehyde and alcohol functional groups.

### Step 3: Identify the Keny-Zarrow Reaction
The Keny-Zarrow reaction is the opposite of aldol condensation. It involves aldehydes and ketones that do not have alpha hydrogens. When treated with a base, these compounds do not undergo aldol condensation but instead yield products characteristic of the Keny-Zarrow reaction.

### Step 4: Evaluate Each Statement
1. **Statement 1**: "Aldol condensation is given by aldehyde in presence of alkali."
- This statement is true because aldehydes with alpha hydrogens can undergo aldol condensation in the presence of a base.

2. **Statement 2**: "Aldol condensation is given by aldehyde and ketone in presence of acid."
- This statement is misleading. Aldol condensation typically occurs in the presence of a base, not acid. Therefore, this statement is false.

3. **Statement 3**: "Keny-Zarrow reaction is given by aldehyde in presence of alkali."
- This statement is false if the aldehyde has alpha hydrogens. The Keny-Zarrow reaction requires the absence of alpha hydrogens.

### Step 5: Conclusion
Based on the analysis, we find that:
- Statement 2 is false because aldol condensation does not occur in the presence of acid.
- Statement 3 is also false, depending on the aldehyde used.

However, since we need to identify only one false statement, we conclude that the most clearly false statement is Statement 2.

### Final Answer
The false statement is: **"Aldol condensation is given by aldehyde and ketone in presence of acid."**

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