To prepare 2-propanol from methylmagnesium bromide, the other chemical required is

Options

A. HCHO
B. `CH_(3)CHO`
C. `C_(2)H_(5)OH`
D. `O=C=O`

Answer

To prepare 2-propanol from methylmagnesium bromide (CH3MgBr), we need to identify the appropriate reactant from the given options. The options provided are:

A) HCHO (formaldehyde)
B) CH3CHO (acetaldehyde)
C) C2H5OH (ethanol)
D) CO2 (carbon dioxide)

### Step-by-Step Solution:

1. **Understanding the Grignard Reagent**:
Methylmagnesium bromide (CH3MgBr) is a Grignard reagent. Grignard reagents react with carbonyl compounds to form alcohols after hydrolysis.

2. **Identifying the Target Product**:
The target product is 2-propanol, which has the structure CH3-CHOH-CH3. This molecule contains three carbon atoms.

3. **Analyzing the Carbon Count**:
Since we need to form a product with three carbon atoms (2-propanol), the reactant must provide at least two additional carbon atoms when reacting with the one carbon from CH3MgBr.

4. **Evaluating Each Option**:
- **Option A: HCHO (formaldehyde)**
- Contains 1 carbon atom.
- Reaction: CH3MgBr + HCHO → CH3-CH2OH (1 carbon from HCHO + 1 from CH3MgBr = 2 carbons).
- Not suitable as it cannot form 2-propanol.

- **Option B: CH3CHO (acetaldehyde)**
- Contains 2 carbon atoms.
- Reaction: CH3MgBr + CH3CHO → CH3-CH(OH)-CH3 (2 carbons from CH3CHO + 1 from CH3MgBr = 3 carbons).
- This reaction can yield 2-propanol, making it a suitable option.

- **Option C: C2H5OH (ethanol)**
- Contains 2 carbon atoms.
- Reaction: CH3MgBr + C2H5OH does not yield a suitable electrophilic carbon for the Grignard reagent to attack, so it will not form 2-propanol.

- **Option D: CO2 (carbon dioxide)**
- Contains 1 carbon atom.
- Reaction: CH3MgBr + CO2 → CH3COOMgBr, which upon hydrolysis gives CH3COOH (acetic acid), not 2-propanol.

5. **Conclusion**:
The only reactant that can yield 2-propanol when reacted with methylmagnesium bromide is **option B: CH3CHO (acetaldehyde)**.

### Final Answer:
**The other chemical required is CH3CHO (acetaldehyde).**