Question 141 markSection A

$Assertion (A): The presence of -OH group in phenols directs the incoming group to meta position in the ring. Reason (R): -OH group in phenols activates the aromatic ring towards electrophilic substitution reaction.$

Q: Assertion (A): The presence of –OH group in phenols directs the incoming group to meta position in the ring. Reason (R): –OH group in phenols activates the aromatic ring towards electrophilic substitution reaction.

**Correct option: (D)** — Assertion is false, but Reason is true. **Why A is false:** - The –OH group is an **ortho / para-directing** group, not meta-directing. - Its oxygen lone pair delocalises into the ring, building up negative charge at the ortho and para positions, where the electrophile attacks. **Why R is true:** - The same electron donation by –OH increases the electron density of the ring, so phenol **is more reactive** (activated) towards electrophilic substitution than benzene. - Hence R is a correct standalone statement, but it does not support the incorrect assertion.

Alcohols, Phenols and Ethers

Directive influence of -OH in phenol

Options

(A)

Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).

(B)

Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).

(C)

Assertion (A) is true, but Reason (R) is false.

(D)

Assertion (A) is false, but Reason (R) is true.

Official answer

Correct option: (D) — Assertion is false, but Reason is true. Why A is false: The -OH group is an ortho / para-directing group, not meta-directing. Its oxygen lone pair delocalises into the ring, building up negative charge at the ortho and para positions, where the electrophile attacks. Why R is true: The same electron donation by -OH increases the electron density of the ring, so phenol is more reactive (activated) towards electrophilic substitution than benzene. Hence R is a correct standalone statement, but it does not support the incorrect assertion.

phenol

ortho para directing

activating group

electrophilic substitution

resonance

lone pair donation

hydroxyl group

ring activation

Marking scheme

1. $1 mark: correct code (D) — Assertion false (-OH is o/p-directing, not meta), Reason true (-OH activates the ring).$
2. $Full mark for (D); no partial credit.$

Hint

$Recall that -OH donates electrons by resonance — that makes it activating AND ortho/para-directing, never meta.$

Quick oral answer

$The assertion is false and the reason is true: the -OH group activates the ring and directs electrophiles to the ortho and para positions, not the meta position, so the correct code is (D).$

Common mistakes

1. $Selecting (A) because the reason sounds correct — but the assertion's 'meta' claim is wrong.$
2. $Confusing electron-donating groups (o/p-directing) with electron-withdrawing groups like -NO₂ (meta-directing, deactivating).$
3. $Assuming an activating group must automatically direct meta; activation and o/p direction go together for -OH.$

Analysis and explanation

Concept: Groups attached to a benzene ring are classified by how they steer an incoming electrophile. The -OH group of phenol is a strong activating, ortho/para-directing group. Mechanistic reason: The lone pair on oxygen enters into resonance with the ring. This places extra electron density specifically at the ortho and para carbons, making those the sites of electrophilic attack. The overall higher ring electron density also makes phenol far more reactive than benzene — for example it undergoes bromination even with bromine water. Exam trap: The reason (activation) is a genuinely true statement, tempting students to pick (A). But the assertion wrongly claims meta direction. Correct pairing: true reason, false assertion \to code (D). Real-world: The strong o/p-activating nature of -OH is why phenol gives 2,4,6-tribromophenol (a white precipitate) instantly with bromine water, a classic qualitative test.

Interesting facts

$Phenol is roughly a thousand times more reactive than benzene toward electrophilic substitution because of -OH resonance donation.$

$The o/p-directing power of -OH is so strong that phenol reacts with dilute nitric acid at room temperature, whereas benzene needs a hot nitrating mixture of conc. HNO₃ and conc. H₂SO₄.$

Question details

Q14 of 37 questions

Board: CBSE
Class: Class 12
Subject: Chemistry
Year: 2026
Section: Section A
Marks: 1
Chapter: Alcohols, Phenols and Ethers
Topic: $Directive influence of -OH in phenol$
Bloom's level: understand
Syllabus topic: $Unit: Alcohols, Phenols and Ethers — Electrophilic Aromatic Substitution of Phenol$
Author: CBSE
Reviewed by: Padhantu Academic Team

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Frequently asked questions

$Is the -OH group in phenol ortho/para-directing or meta-directing?$

$It is ortho/para-directing. The lone pair on oxygen is donated into the ring by resonance, raising electron density at the ortho and para positions, so electrophiles attack there rather than at the meta position.$

$Why is phenol more reactive than benzene in electrophilic substitution?$

$The -OH group is an activating group; its resonance donation of electrons increases the overall electron density of the ring, making it easier for an electrophile to attack. This is why phenol reacts with bromine water and dilute nitric acid under mild conditions.$