Total number of chain isomers possible for `C_(7)H_(16)` are

Answer

To determine the total number of chain isomers possible for the alkane C7H16, we will follow these steps:

### Step 1: Understand the Structure of Alkanes
Alkanes are hydrocarbons with the general formula CnH2n+2. For C7H16, n = 7. This means we are dealing with a saturated hydrocarbon.

### Step 2: Identify the Straight-Chain Isomer
The first isomer is the straight-chain alkane, which is heptane. The structure can be represented as:
- CH3-CH2-CH2-CH2-CH2-CH2-CH3

### Step 3: Identify the Branched Isomers
Next, we will consider the branched isomers. We can create branches by replacing hydrogen atoms with methyl (CH3) groups.

1. **One branch**:
- 2-Methylhexane:
- CH3-CH(CH3)-CH2-CH2-CH2-CH3
- 3-Methylhexane:
- CH3-CH2-CH(CH3)-CH2-CH2-CH3

2. **Two branches**:
- 2,2-Dimethylpentane:
- CH3-C(CH3)2-CH2-CH2-CH3
- 2,3-Dimethylpentane:
- CH3-CH(CH3)-CH(CH3)-CH2-CH3
- 3,3-Dimethylpentane:
- CH3-CH2-C(CH3)2-CH2-CH3

3. **Three branches**:
- 2,2,3-Trimethylbutane:
- CH3-C(CH3)2-CH(CH3)-CH3

### Step 4: Count the Isomers
Now, we will count all the unique chain isomers we have identified:
1. Heptane (1)
2. 2-Methylhexane (1)
3. 3-Methylhexane (1)
4. 2,2-Dimethylpentane (1)
5. 2,3-Dimethylpentane (1)
6. 3,3-Dimethylpentane (1)
7. 2,2,3-Trimethylbutane (1)

### Total Number of Chain Isomers
Adding these together, we find that the total number of chain isomers for C7H16 is **9**.

### Final Answer
The total number of chain isomers possible for C7H16 is **9**.

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