In which reaction halide is not obtained

Options

A. `R-OH+Nato`
B. `R-OH+H-Brto`
C. `R-OH+SOCl_(2)to`
D. `R-OH+PCl_(5)to`

Answer

To determine in which reaction halide is not obtained, we will analyze the provided reactions involving alcohols (ROH) with different reagents.

### Step-by-Step Solution:

1. **Identify the Reactions**: We have four reactions involving alcohols (ROH) and different reagents:
- Reaction 1: ROH + Na
- Reaction 2: ROH + HBr
- Reaction 3: ROH + Thionyl Chloride (SOCl2)
- Reaction 4: ROH + PCl5

2. **Analyze Reaction 1 (ROH + Na)**:
- In this reaction, alcohol reacts with sodium (an active metal).
- The products formed are sodium alkoxide (R-O-Na) and hydrogen gas (H2).
- There is no halide formed in this reaction.
- **Conclusion**: This reaction does not produce a halide.

3. **Analyze Reaction 2 (ROH + HBr)**:
- Here, alcohol reacts with hydrobromic acid (HBr).
- The products formed are alkyl bromide (RBr) and water (H2O).
- **Conclusion**: This reaction produces a halide (RBr).

4. **Analyze Reaction 3 (ROH + Thionyl Chloride)**:
- In this reaction, alcohol reacts with thionyl chloride (SOCl2).
- The products formed are alkyl chloride (RCl), sulfur dioxide (SO2), and hydrogen chloride (HCl).
- **Conclusion**: This reaction produces a halide (RCl).

5. **Analyze Reaction 4 (ROH + PCl5)**:
- Here, alcohol reacts with phosphorus pentachloride (PCl5).
- The products formed are alkyl chloride (RCl), phosphorus oxychloride (POCl3), and hydrogen chloride (HCl).
- **Conclusion**: This reaction also produces a halide (RCl).

6. **Final Conclusion**:
- Among the four reactions analyzed, only the first reaction (ROH + Na) does not produce a halide.
- Therefore, the answer to the question "In which reaction halide is not obtained?" is **Reaction 1: ROH + Na**.