The total number of structural ethers possible with the molecular formula `C_5H_(12)O` ?

Options

A. 4
B. 5
C. 6
D. 7

Answer

To determine the total number of structural ethers possible with the molecular formula \( C_5H_{12}O \), 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 molecular formula \( C_5H_{12}O \) indicates that we have a total of 5 carbon atoms, 12 hydrogen atoms, and 1 oxygen atom.

### Step 2: Determine Possible Alkyl Groups
Since we need to form ethers, we can consider different combinations of alkyl groups that can be derived from 5 carbon atoms. The alkyl groups can be straight-chain or branched.

### Step 3: Identify Structural Isomers
1. **Straight-chain Ethers**:
- The simplest ether can be formed by taking two straight chains of carbons. For example, one possible ether is \( CH_3-CH_2-CH_2-O-CH_3 \) (butyl methyl ether).
- Another example is \( CH_3-CH_2-O-CH_2-CH_3 \) (ethyl ether).

2. **Branched Ethers**:
- We can also create ethers with branched structures. For instance, \( CH_3-O-CH(CH_3)-CH_2-CH_3 \) (isopropyl ether).
- Other combinations can include variations with different placements of the oxygen atom among the carbon chains.

### Step 4: Count All Unique Isomers
After systematically considering the combinations, we can list out the unique structural isomers:
1. \( CH_3-CH_2-CH_2-O-CH_3 \) (butyl methyl ether)
2. \( CH_3-CH_2-O-CH_2-CH_3 \) (ethyl ether)
3. \( CH_3-O-CH_2-CH_2-CH_3 \) (methoxypropane)
4. \( CH_3-O-CH(CH_3)-CH_2-CH_3 \) (isopropyl ether)
5. \( CH_3-CH(CH_3)-O-CH_2-CH_3 \) (2-methyl-1-butyl ether)
6. \( CH_3-CH_2-CH(O)-CH_2-CH_3 \) (2-pentanol ether)

### Conclusion
After analyzing the combinations and ensuring that all structural isomers are accounted for, we find that there are a total of **6 structural ethers** possible with the molecular formula \( C_5H_{12}O \).

### Final Answer
The total number of structural ethers possible with the molecular formula \( C_5H_{12}O \) is **6**.

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