Given below are two statements — Assertion A and Reason R: Assertion A: Butan-1-ol has higher boiling point than…
Chemical Bonding · Class 11 · JEE Main Previous Year Question
Given below are two statements — Assertion A and Reason R:
Assertion A: Butan-1-ol has higher boiling point than ethoxyethane.
Reason R: Extensive hydrogen bonding leads to stronger association of molecules.
Choose the correct answer:
- a
A is true but R is false
- b✓
Both A and R are true and R is the correct explanation of A
- c
Both A and R are true but R is not the correct explanation of A
- d
A is false but R is true
Both A and R are true and R is the correct explanation of A
🧠 Compare boiling points of butan-1-ol vs ethoxyethane (diethyl ether) — same molecular formula but different H-bonding ability.
🗺️ Evaluate Assertion A:
- Butan-1-ol (): has O–H group → forms intermolecular H-bonds → bp ≈ 117 °C
- Ethoxyethane (): no O–H group → only van der Waals forces → bp ≈ 34 °C
- Butan-1-ol has higher boiling point → A is TRUE ✓
Evaluate Reason R:
- Butan-1-ol molecules associate extensively via O–H···O hydrogen bonds → extra energy needed to vaporise
- Ethoxyethane lacks O–H → no such association
- R is TRUE ✓ and R correctly explains A ✓
Practice this question with progress tracking
Want timed practice with adaptive difficulty? Solve this question (and hundreds more from Chemical Bonding) inside The Crucible, our adaptive practice platform.
More JEE Main Chemical Bonding PYQs
The correct statement(s) about Hydrogen bonding is/are: A. Hydrogen bonding exists when H is covalently bonded to a highly electronegative atom. B. Intermolecular H bonding is present in…
Given below are two statements — Assertion (A) and Reason (R): Assertion (A): PH3 has lower boiling point than NH3. Reason (R): In liquid state, NH3 molecules are associated through hydrogen bonding,…
Select the compound from the following that will show intramolecular hydrogen bonding:
Decreasing order of the hydrogen bonding in following forms of water is correctly represented by: A. Liquid water B. Ice C. Impure water
The correct order of increasing intermolecular hydrogen bond strength is