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 will analyze each statement one by one.

### Step-by-Step Solution:

**Step 1: Analyze the first statement**
- The first statement claims that the Canizzaro reaction is given by aldehydes in the presence of alkali.
- The Canizzaro reaction occurs for aldehydes that do not have alpha hydrogen atoms (e.g., benzaldehyde, formaldehyde) when treated with a strong base.
- In this reaction, one aldehyde molecule is oxidized to a carboxylic acid, while another is reduced to an alcohol.
- Example: 2 HCHO (formaldehyde) + NaOH → CH3OH (methyl alcohol) + HCOONa (sodium formate).
- **Conclusion**: This statement is true.

**Step 2: Analyze the second statement**
- The second statement states that aldol condensation is given by aldehydes in the presence of alkali.
- Aldol condensation occurs when aldehydes or ketones with alpha hydrogen atoms react in the presence of a dilute base to form beta-hydroxy aldehydes or ketones.
- Example: 2 CH3CHO (acetaldehyde) in the presence of NaOH forms 3-hydroxybutanal, which can further dehydrate to form but-2-enal.
- **Conclusion**: This statement is true.

**Step 3: Analyze the third statement**
- The third statement claims that aldol condensation is given by aldehydes and ketones in the presence of acid.
- Aldol condensation primarily occurs in the presence of a base, but it can also occur under acidic conditions, although the mechanism differs.
- The presence of acid can facilitate the formation of enol or enolate forms, leading to condensation.
- **Conclusion**: This statement is also true.

**Step 4: Analyze the fourth statement**
- The fourth statement claims that none of the above statements are false.
- Since we have established that all previous statements (1, 2, and 3) are true, this statement must also be true.
- **Conclusion**: This statement is true.

### Final Conclusion:
Since all the statements provided (1, 2, and 3) are true, the statement that "none of these statements are false" is also true. Therefore, there is no false statement among the options provided.

### Answer:
None of the above statements are false.