Which of the following will show cannizzaro reaction `:`

Options

A.
B.
C.
D. All of these

Answer

To determine which of the given compounds will show the Cannizzaro reaction, we need to understand the conditions required for this reaction to occur.

### Step-by-Step Solution:

1. **Understanding the Cannizzaro Reaction:**
- The Cannizzaro reaction occurs with aldehydes that do not have alpha hydrogens. In this reaction, one molecule of the aldehyde is oxidized to a carboxylic acid, while another molecule is reduced to an alcohol in the presence of a strong base (like NaOH).

2. **Identifying the Aldehydes:**
- We need to analyze the given compounds to check for the presence of alpha hydrogens. Aldehydes with no alpha hydrogen will undergo the Cannizzaro reaction.

3. **Analyzing Each Compound:**
- **Compound 1: Benzaldehyde (C6H5CHO)**
- Benzaldehyde has no alpha hydrogen (the carbon adjacent to the carbonyl carbon is not attached to any hydrogen). Therefore, it will undergo the Cannizzaro reaction.

- **Compound 2: Formaldehyde (HCHO)**
- Formaldehyde does not have any alpha hydrogen either. It will also undergo the Cannizzaro reaction.

- **Compound 3: Glyoxal (O=CH-CHO)**
- Glyoxal has two carbonyl groups but does not have any alpha hydrogen. Therefore, it will also undergo the Cannizzaro reaction.

4. **Conclusion:**
- Since all three compounds (Benzaldehyde, Formaldehyde, and Glyoxal) do not have alpha hydrogens, they will all show the Cannizzaro reaction.

### Final Answer:
All of the compounds listed will show the Cannizzaro reaction.