`H_(2)C=O+D_(2)C=O+cons. NaOHrarr"Cannizzaro's reaction."`
How many different alcohols would be formed in the reactions.

Answer

To solve the problem regarding the Cannizzaro reaction involving the aldehydes H₂C=O (formaldehyde) and D₂C=O (deuterated formaldehyde), we will analyze the reaction step by step.

### Step 1: Understanding the Cannizzaro Reaction
The Cannizzaro reaction occurs with aldehydes that do not have alpha-hydrogens. In this reaction, one molecule of aldehyde is oxidized to a carboxylic acid while another molecule is reduced to an alcohol. In our case, we have two different aldehydes: formaldehyde (H₂C=O) and deuterated formaldehyde (D₂C=O).

**Hint:** Remember that the Cannizzaro reaction involves the disproportionation of aldehydes without alpha-hydrogens.

### Step 2: Identifying the Aldehydes
We have:
1. H₂C=O (formaldehyde)
2. D₂C=O (deuterated formaldehyde)

**Hint:** Identify the functional groups and their isotopes clearly.

### Step 3: Mechanism of the Reaction
In the presence of a strong base (like NaOH), the aldehydes will undergo the Cannizzaro reaction. The hydroxide ion (OH⁻) will attack the carbonyl carbon of one aldehyde molecule, leading to the formation of an alkoxide intermediate.

**Hint:** Focus on the nucleophilic attack by hydroxide ions on the carbonyl carbon.

### Step 4: Formation of Alcohols
1. **From H₂C=O:**
- One molecule of H₂C=O will be reduced to CH₂OH (methanol).

2. **From D₂C=O:**
- One molecule of D₂C=O will be reduced to CD₂OH (deuterated methanol).

**Hint:** Keep track of which aldehyde is being reduced to which alcohol.

### Step 5: Considering Different Combinations
Now, we need to consider the combinations of the two aldehydes:
1. H₂C=O can produce CH₂OH.
2. D₂C=O can produce CD₂OH.
3. If H₂C=O reacts with D⁻ (from D₂C=O), it will form HCDOH (a mixed alcohol).
4. If D₂C=O reacts with H⁻ (from H₂C=O), it will form H₂C(OH)D (another mixed alcohol).

**Hint:** Consider all possible combinations of H and D in the products.

### Step 6: Listing the Different Alcohols
From the above analysis, we can summarize the different alcohols formed:
1. CH₂OH (from H₂C=O)
2. CD₂OH (from D₂C=O)
3. HCDOH (mixed alcohol from H₂C=O and D₂C=O)
4. H₂C(OH)D (mixed alcohol from D₂C=O and H₂C=O)

### Conclusion
In total, we have four different alcohols formed from the Cannizzaro reaction of H₂C=O and D₂C=O.

**Final Answer:** Four different alcohols are formed.