Assertion (A) : `CH_(3)OCH_(3) and C_(2)H_(5)OH` has comparable molecular weight but boiling point of `C_(2)H_(5)OH` is more than dimethyl ether.
Reason (R) : `C_(2)H_(5)OH` forms intermolecular. H-bonding while `CH_(3)OCH_(3)` forms intramolecular H-bonding.

Options

A. If both A and R are true and R is the correct explanation of A.
B. If both A and R are true but R is not the correct explanation of A.
C. If A is true but R is false
D. If A is false but R is true.

Explanation

To solve the question, we need to evaluate both the assertion (A) and the reason (R) provided.

### Step 1: Analyze the Assertion (A)
The assertion states that CH3OCH3 (dimethyl ether) and C2H5OH (ethanol) have comparable molecular weights, but the boiling point of C2H5OH is higher than that of dimethyl ether.

- **Molecular Weights**:
- CH3OCH3 (dimethyl ether): The molecular weight is approximately 46 g/mol (C: 12, H: 3*1, O: 16).
- C2H5OH (ethanol): The molecular weight is also approximately 46 g/mol (C: 2*12, H: 5*1, O: 16).

Both compounds have comparable molecular weights.

- **Boiling Points**:
- Boiling point of CH3OCH3 (dimethyl ether) is about -24.9 °C.
- Boiling point of C2H5OH (ethanol) is about 78.37 °C.

Thus, the assertion is true: C2H5OH does have a higher boiling point than CH3OCH3.

### Step 2: Analyze the Reason (R)
The reason states that C2H5OH forms intermolecular hydrogen bonding while CH3OCH3 forms intramolecular hydrogen bonding.

- **Hydrogen Bonding in C2H5OH**:
Ethanol (C2H5OH) has an -OH group that allows for strong intermolecular hydrogen bonding between molecules. This is due to the presence of a hydrogen atom attached to the highly electronegative oxygen atom.

- **Hydrogen Bonding in CH3OCH3**:
Dimethyl ether (CH3OCH3) does not have hydrogen atoms directly bonded to oxygen, so it does not form significant hydrogen bonds. Instead, it can only form weak dipole-dipole interactions.

Thus, the reason is also true: C2H5OH forms strong intermolecular hydrogen bonds, while CH3OCH3 does not form significant hydrogen bonds.

### Conclusion
- Assertion (A) is true.
- Reason (R) is true, but it incorrectly states that CH3OCH3 forms intramolecular hydrogen bonding, which is not significant in this case.

### Final Answer
The correct answer is that Assertion (A) is true, and Reason (R) is true but does not correctly explain Assertion (A). Therefore, the answer is **C**: Assertion is true, Reason is true but does not support Assertion.

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