Total number of ethers possible with the molecular formula `C_5H_(12)O` exhibiting constitutional isomerism is

Options

A. `3`
B. `4`
C. `5`
D. `6`

Explanation

To determine the total number of ethers possible with the molecular formula \( C_5H_{12}O \) that exhibit constitutional isomerism, we can follow these steps:

### Step 1: Understand the Structure of Ethers
Ethers have the general structure \( R-O-R' \), where \( R \) and \( R' \) are alkyl groups. The total number of carbon atoms in the ether must equal 5, and there must be one oxygen atom.

### Step 2: Identify Possible Alkyl Groups
We need to consider how we can arrange 5 carbon atoms into two alkyl groups. The possible combinations of carbon atoms in the two alkyl groups must add up to 5.

### Step 3: List Possible Combinations
1. **Straight Chain Ethers:**
- 5 carbons in one chain: \( CH_3-CH_2-CH_2-CH_2-CH_2-O- \) (Pentyl ether)

2. **Branched Ethers:**
- 4 carbons in one chain and 1 carbon in another:
- \( CH_3-CH_2-CH_2-CH_2-O-CH_3 \) (Butyl methyl ether)
- \( CH_3-CH_2-CH(O-CH_3)-CH_3 \) (Isobutyl methyl ether)
- 3 carbons in one chain and 2 in another:
- \( CH_3-CH(O-CH_2-CH_3)-CH_2-CH_3 \) (Propyl ethyl ether)
- \( CH_3-O-CH_2-CH_2-CH_2-CH_3 \) (Ethyl propyl ether)

3. **More Complex Structures:**
- 2 carbons in one chain and 3 in another:
- \( CH_3-CH(O-CH_3)-CH_2-CH_2-CH_3 \) (Isopropyl butyl ether)
- 1 carbon in one chain and 4 in another:
- \( CH_3-O-CH_2-CH_2-CH_2-CH_2-CH_3 \) (Butyl ether)

### Step 4: Count the Unique Structures
After identifying the possible combinations, we can summarize the unique ethers:
1. Pentyl ether
2. Butyl methyl ether
3. Isobutyl methyl ether
4. Propyl ethyl ether
5. Isopropyl butyl ether
6. Butyl ether

### Conclusion
The total number of ethers possible with the molecular formula \( C_5H_{12}O \) exhibiting constitutional isomerism is **6**.

### Final Answer
The correct option is **D: 6**.

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