Chapter Exam

Chapter 12: Basic concepts of organic reactions — Online MCQ Test

Q: Which of the following species acts as an electrophile?

Answer: B. BF3 — BF3 is an electron-deficient molecule with an incomplete octet, making it a Lewis acid or electrophile.

Q: The permanent displacement of a shared pair of electrons in a carbon chain due to the difference in electronegativity is called:

Answer: B. Inductive effect — Inductive effect is the permanent displacement of sigma electrons along a chain due to electronegativity differences.

Q: Which effect is a temporary electronic effect?

Answer: C. Electromeric effect — Electromeric effect operates only in the presence of an attacking reagent and vanishes when the reagent is removed.

Q: Which of the following pairs represents resonance structures?

Answer: B. CH2=CH-CH=O and -CH2-CH=CH-O+ — Resonance structures involve the shift of pi or lone pair electrons without changing atomic positions.

Q: In the reaction CH3-CH2-Br + OH- -> CH3-CH2-OH + Br-, the OH- ion acts as a:

Answer: B. Nucleophile — The hydroxide ion donates an electron pair to the carbon atom, acting as a nucleophile.

CHEMISTRY · CLASS 11th · Tamil Nadu State Board

Practice Chapter 12: Basic concepts of organic reactions with a free chapter-wise online MCQ test for Tamil Nadu State Board CLASS 11th CHEMISTRY. This chapter covers: Focusing on reaction mechanisms this chapter details covalent bond cleavage inductive electromeric resonance and hyperconjugation effects. Students examine electrophiles nucleophil.... AI-generated questions from basic to board-exam level, with instant results and explanations.

Questions

20m

Time Limit

Attempts Left

10 random questions from this chapter (mixed difficulty)
Questions you've seen before won't repeat until the pool resets
You have 20 minutes — exam auto-submits when time is up
Maximum 3 attempts per chapter
Results and explanations shown immediately after submission

New here? Register free — includes 3 free chapter exams.

Chapter 12: Basic concepts of organic reactions — Important Questions & Answers (FAQ)

Frequently asked questions from Tamil Nadu State Board CLASS 11th CHEMISTRY — Chapter 12: Basic concepts of organic reactions, with answers and explanations. These are sample questions; the exam has its own separate question set.

Which of the following species acts as an electrophile?

A. NH3
B. BF3 ✓
C. H2O
D. ROH

Answer: B. BF3
BF3 is an electron-deficient molecule with an incomplete octet, making it a Lewis acid or electrophile.

The permanent displacement of a shared pair of electrons in a carbon chain due to the difference in electronegativity is called:

A. Electromeric effect
B. Inductive effect ✓
C. Hyperconjugation
D. Resonance

Answer: B. Inductive effect
Inductive effect is the permanent displacement of sigma electrons along a chain due to electronegativity differences.

Which effect is a temporary electronic effect?

A. Inductive effect
B. Resonance
C. Electromeric effect ✓
D. Hyperconjugation

Answer: C. Electromeric effect
Electromeric effect operates only in the presence of an attacking reagent and vanishes when the reagent is removed.

Which of the following pairs represents resonance structures?