Number of structural isomers of `C_4H_(10)O` that are ethers are

Options

A. 1
B. 2
C. 3
D. 4

Answer

To determine the number of structural isomers of \( C_4H_{10}O \) that are ethers, we will follow these steps:

### Step 1: Understand the structure of ethers
Ethers have the general formula \( R-O-R' \), where \( R \) and \( R' \) are alkyl groups. In our case, we need to arrange 4 carbon atoms and 1 oxygen atom in such a way that they form ethers.

### Step 2: Identify possible alkyl groups
Given that we have 4 carbon atoms, we can have different combinations of these carbon atoms in the alkyl groups. The possible combinations of carbon skeletons that can be formed are:
- Two methyl groups (CH3) and two ethyl groups (C2H5)
- One butyl group (C4H9) and one methyl group (CH3)
- One propyl group (C3H7) and one ethyl group (C2H5)

### Step 3: List the structural isomers
1. **Dimethyl ether**: \( CH_3-O-CH_3 \)
2. **Ethyl methyl ether**: \( CH_3-CH_2-O-CH_3 \)
3. **Diethyl ether**: \( CH_3-CH_2-O-CH_2-CH_3 \)

### Step 4: Verify the structures
- **Dimethyl ether**: Contains 2 carbon atoms from each methyl group, totaling 4 carbon atoms and 10 hydrogen atoms, with 1 oxygen atom.
- **Ethyl methyl ether**: Contains 2 carbon atoms from the ethyl group and 1 from the methyl group, totaling 4 carbon atoms and 10 hydrogen atoms, with 1 oxygen atom.
- **Diethyl ether**: Contains 2 carbon atoms from each ethyl group, totaling 4 carbon atoms and 10 hydrogen atoms, with 1 oxygen atom.

### Step 5: Conclusion
After analyzing the possible structures, we find that there are **3 structural isomers** of \( C_4H_{10}O \) that are ethers.

### Final Answer
The number of structural isomers of \( C_4H_{10}O \) that are ethers is **3**.

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