Given below are the structure of few compounds with molecular formula `C_(4)H_(10)O`. Select metamers from these structure.
(i) `CH_(3)-O-CH_(2)CH_(2)CH_(3)`
(ii) `CH_(3)CH_(2)CH_(2)CH_(2)OH`
(iii) `CH_(3)-CH_(2)-O-CH_(2)-CH_(3)`
(iv) `CH_(3)-underset(OH)underset("| ")"CH"-CH_(2)-CH_(3)`

Options

A. (i) and (ii)
B. (ii) and (iii)
C. (i) and (iii)
D. (ii) and (iv)

Answer

To solve the question of identifying metamers from the given structures with the molecular formula C4H10O, we need to understand the concept of metamers. Metamers are compounds that have the same molecular formula but differ in the arrangement of carbon atoms around the functional group.

### Step-by-Step Solution:

1. **Identify the Compounds**:
- (i) `CH3-O-CH2CH2CH3`
- (ii) `CH3CH2CH2CH2OH`
- (iii) `CH3-CH2-O-CH2-CH3`
- (iv) `CH3-CH(OH)-CH2-CH3`

2. **Analyze Compound (i)**:
- Structure: `CH3-O-CH2CH2CH3`
- This is an ether with a methoxy group (CH3O-) and a propyl group (CH2CH2CH3).
- Possible metamer: `CH3CH2OCH2CH3` (which has 2 carbons on one side and 2 on the other side).

3. **Analyze Compound (ii)**:
- Structure: `CH3CH2CH2CH2OH`
- This is a straight-chain alcohol (butanol).
- Cannot form a metamer because it has only one arrangement of carbon atoms around the functional group (OH).

4. **Analyze Compound (iii)**:
- Structure: `CH3-CH2-O-CH2-CH3`
- This is another ether with an ethoxy group (CH3-CH2O-) and an ethyl group (CH2-CH3).
- This can be considered a metamer of compound (i) since they differ in the arrangement of carbon atoms around the ether functional group.

5. **Analyze Compound (iv)**:
- Structure: `CH3-CH(OH)-CH2-CH3`
- This is a butanol with the hydroxyl group on the second carbon (2-butanol).
- This is a positional isomer of compound (ii) but not a metamer.

6. **Conclusion**:
- The compounds that are metamers are (i) `CH3-O-CH2CH2CH3` and (iii) `CH3-CH2-O-CH2-CH3`.
- Therefore, the answer is that the metamers are the first and third compounds.

### Final Answer:
The metamers from the given structures are (i) and (iii).