Classify the following compounds as primary, secondary and tertiary halides.
(i) 1-bromobut-2-ene
(ii). 4-Bromopent-2-ene
(iii). 2-Bromo-2-methylpropane

Options

A. (i)-secondary,(ii)-tertiary,(iii)-primary
B. (i)-secondary,(ii)-primary,(iii)-tertiary
C. (i)-primary,(ii)-tertiary,(iii)-secondary
D. (i)-primary,(ii)-secondary,(iii)-tertiary

Answer

To classify the given compounds as primary, secondary, or tertiary halides, we need to analyze the structure of each compound and determine the type of carbon atom to which the halogen (bromine in this case) is attached.

### Step-by-Step Solution:

1. **Understanding the Definitions**:
- **Primary Halide**: The halogen is attached to a primary carbon, which is bonded to only one other carbon.
- **Secondary Halide**: The halogen is attached to a secondary carbon, which is bonded to two other carbons.
- **Tertiary Halide**: The halogen is attached to a tertiary carbon, which is bonded to three other carbons.

2. **Analyzing the First Compound: 1-bromobut-2-ene**:
- Structure:
- The compound has a four-carbon chain (butene) with a bromine atom at the first carbon and a double bond between the second and third carbons.
- The carbon to which the bromine is attached (C1) is connected to only one other carbon (C2).
- Conclusion: Since the bromine is attached to a primary carbon, **1-bromobut-2-ene is a primary halide**.

3. **Analyzing the Second Compound: 4-bromopent-2-ene**:
- Structure:
- This compound has a five-carbon chain (pentene) with a bromine atom at the fourth carbon and a double bond between the second and third carbons.
- The carbon to which the bromine is attached (C4) is connected to two other carbons (C3 and C5).
- Conclusion: Since the bromine is attached to a secondary carbon, **4-bromopent-2-ene is a secondary halide**.

4. **Analyzing the Third Compound: 2-bromo-2-methylpropane**:
- Structure:
- This compound has a three-carbon chain with a methyl group at the second carbon and a bromine atom also at the second carbon.
- The carbon to which the bromine is attached (C2) is connected to three other carbons (C1, C3, and the methyl group).
- Conclusion: Since the bromine is attached to a tertiary carbon, **2-bromo-2-methylpropane is a tertiary halide**.

### Final Classification:
- (i) 1-bromobut-2-ene: **Primary Halide**
- (ii) 4-bromopent-2-ene: **Secondary Halide**
- (iii) 2-bromo-2-methylpropane: **Tertiary Halide**