Organic Chemistry — Basic Principles and Techniques — Class 11 MCQs with Answers
Class 11 CBSE Chemistry · Chapter 8
90 practice questions · 30 Easy · 30 Medium · 30 Hard · Updated
Practise the most important Class 11 CBSE Chemistry questions from Chapter 8, "Organic Chemistry — Basic Principles and Techniques". You get 9 timed quizzes made from 90 NCERT-based MCQs, with answers and explanations. The questions are split into 30 Easy, 30 Medium and 30 Hard. Warm up on the basics, then move on to the exam-level questions that set top scorers in CBSE & Maharashtra HSC Board exams, JEE Main, MHT-CET, JEE Advanced and NEET UG apart.
To score well in "Organic Chemistry — Basic Principles and Techniques", focus on reactions, key concepts and careful numericals. Each MCQ here is timed and uses exam-style marking (+4 correct, −1 wrong, 0 skipped). This trains you to stay accurate under time pressure, as real papers need. Every question has a short explanation, so a wrong answer becomes a quick lesson. It is the fastest way to fix gaps before a test.
Use this chapter for focused revision. Start with the Easy set to check your basics on Organic Chemistry — Basic Principles and Techniques, then move to Medium and Hard to practise applying them. Your accuracy, streaks and XP save automatically. This chapter also adds to your overall Class 11 Chemistry mastery score. 14 sample questions are solved in full below, with the answer and a worked explanation. Sign in free to start practising.
Key concepts: Organic Chemistry — Basic Principles and Techniques (Class 11 Chemistry)
Organic chemistry begins with carbon's ability to catenate and form four bonds. This chapter sets the ground rules: IUPAC nomenclature, structural and stereo isomerism, sp/sp²/sp³ hybridisation, the electronic effects that steer reactivity, the reaction intermediates, and the core reaction types and purification methods.
- Catenation & tetravalency
- Carbon forms four covalent bonds and links to itself in long chains and rings (catenation), which is the source of organic molecules' huge diversity.
- Hybridisation of carbon
- sp³ is tetrahedral 109.5° (alkanes), sp² trigonal planar 120° (alkenes), sp linear 180° (alkynes); s-character rises sp³ < sp² < sp.
- Sigma and pi bonds
- A σ bond forms by head-on overlap and allows free rotation; a π bond forms by sidewise p-overlap, is weaker and locks geometry, blocking rotation.
- IUPAC nomenclature
- Name = locants + substituents (alphabetical) + root (longest chain) + suffix (principal functional group), numbered to give the lowest locant set.
Organic Chemistry — Basic Principles and Techniques — important questions & MCQs with answers (Class 11 Chemistry)
14 solved questions from this chapter's difficulty levels, each with its answer and explanation. The other 76 are timed and scored when you sign in.
- Q1Easy
Functional group −OH belongs to:
A.EsterB.Carboxylic acidC.AldehydeD.Alcohol✓ CorrectAnswer: D. Alcohol
Explanation: The suffix -ol marks the hydroxyl (−OH) functional group, so −OH is an alcohol, e.g. CH₃−OH is methanol. Mixing it up with −COOH (acid, -oic) is the common slip.
- Q2Easy
Compounds with the same molecular formula but different structures are called:
A.AllotropesB.Isomers✓ CorrectC.PolymersD.HomologuesAnswer: B. Isomers
Explanation: Same molecular formula, different arrangement of atoms — that's isomerism, e.g. C₄H₁₀ as n-butane or isobutane. Allotropes are different forms of one element, not compounds.
- Q3Easy
General formula of alkanes:
A.CₙH₂ₙB.CₙH₂ₙ₊₂✓ CorrectC.CₙH₂ₙ₋₂D.CₙHₙAnswer: B. CₙH₂ₙ₊₂
Explanation: Alkanes are saturated (only C−C and C−H single bonds), so each carbon carries the maximum H count: CₙH₂ₙ₊₂. Dropping the +2 gives CₙH₂ₙ, the alkene formula instead.
- Q4Easy
Successive members of a homologous series differ by:
A.−OHB.−CH₃C.−HD.−CH₂−✓ CorrectAnswer: D. −CH₂−
Explanation: Each step up a homologous series adds one −CH₂− (14 u), e.g. CH₄ to C₂H₆ to C₃H₈. Picking −CH₃ or −H ignores that a full methylene unit, not one atom, is added each time.
- Q5Easy
Functional group −CHO is:
A.AlcoholB.KetoneC.Aldehyde✓ CorrectD.AcidAnswer: C. Aldehyde
Explanation: −CHO places the carbonyl at a chain end with one H attached, giving the aldehyde suffix -al. Confusing it with a mid-chain >C=O (ketone, -one) is the usual mix-up.
- Q6Easy
Metamerism is shown by:
A.AldehydesB.Alkanes onlyC.Alcohols onlyD.Ethers, ketones with different alkyl groups around the same functional group✓ CorrectAnswer: D. Ethers, ketones with different alkyl groups around the same functional group
Explanation: Metamers share the same functional group but differ in how alkyl groups are distributed around it, e.g. CH₃-O-C₃H₇ vs C₂H₅-O-C₂H₅ (both ethers). Position isomerism instead moves the group along one fixed chain.
- Q7Medium
IUPAC name of (CH₃)₃C-CH₂-CH₃:
A.2-methylpentaneB.2,2-dimethylbutane✓ CorrectC.3,3-dimethylbutaneD.neopentaneAnswer: B. 2,2-dimethylbutane
Explanation: The longest chain through (CH₃)₃C-CH₂-CH₃ is 4 carbons (butane) with two methyls both on C2, giving 2,2-dimethylbutane. Naming it 2-methylpentane wrongly folds a branch carbon into the main chain.
- Q8Medium
Butane and iso-butane are:
A.Same compoundB.Chain isomers✓ CorrectC.Functional isomersD.EnantiomersAnswer: B. Chain isomers
Explanation: Butane (n-C₄H₁₀) and isobutane (2-methylpropane) share formula C₄H₁₀ but differ only in how the carbon skeleton branches, making them chain isomers, not the same compound.
- Q9Medium
IUPAC name of CH₃-CO-CH₂-CH₃:
A.Propan-2-oneB.Butan-1-oneC.ButanalD.Butan-2-one✓ CorrectAnswer: D. Butan-2-one
Explanation: CH₃-CO-CH₂-CH₃ has a 4-carbon chain with the carbonyl at C2, giving butan-2-one — ketones take the lowest locant for C=O. Butanal would need the carbonyl terminal (C1) with an attached H, which it isn't.
- Q10Medium
Ethanol and dimethyl ether (both C₂H₆O) are:
A.Optical isomersB.Position isomersC.Functional isomers✓ CorrectD.Same compoundAnswer: C. Functional isomers
Explanation: Ethanol (−OH) and dimethyl ether (−O−) both have formula C₂H₆O but carry different functional groups, making them functional isomers. Position isomers need the same group, just relocated — not the case here.
- Q11Medium
IUPAC name of CH₃-CH(OH)-CH₃:
A.Propan-2-ol✓ CorrectB.Propan-1-olC.PropanalD.PropanoneAnswer: A. Propan-2-ol
Explanation: The three-carbon chain has −OH on the middle carbon, C2, giving propan-2-ol. Propan-1-ol would instead place −OH on a terminal carbon, not the middle one shown here.
- Q12Hard
A free-radical intermediate has:
A.Positive chargeB.An unpaired electron✓ CorrectC.Negative chargeD.No bondsAnswer: B. An unpaired electron
Explanation: A free radical such as •CH₃ carries one unpaired electron in an otherwise neutral species, generated by homolytic bond cleavage, which makes it highly reactive. It has no net charge, so charge-based options both misdescribe it.
- Q13Hard
Which compound does NOT show geometrical isomerism?
A.CHCl=CHClB.CH₃CH=CHCH₃C.(CH₃)₂C=CHCH₃✓ CorrectD.CH₃CH=CHClAnswer: C. (CH₃)₂C=CHCH₃
Explanation: Geometrical isomerism needs two different groups on each doubly-bonded carbon; in (CH₃)₂C=CHCH₃ one carbon carries two identical CH₃ groups, so swapping them regenerates the same structure. CHCl=CHCl and CH₃CH=CHCl both do show cis/trans forms.
- Q14Hard
Inductive effect is:
A.Light absorptionB.Magnetic effectC.Permanent polarisation along σ-bonds✓ CorrectD.Heat releaseAnswer: C. Permanent polarisation along σ-bonds
Explanation: The inductive effect is a permanent, weak polarisation of electron density transmitted through σ bonds due to electronegativity differences (−I withdraws, +I donates), decaying with distance. It is a bonding effect, not light, magnetism, or heat.
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Start this chapter free →Organic Chemistry — Basic Principles and Techniques — FAQs
What are the key concepts in Class 11 Chemistry Organic Chemistry — Basic Principles and Techniques?+
Organic chemistry begins with carbon's ability to catenate and form four bonds. This chapter sets the ground rules: IUPAC nomenclature, structural and stereo isomerism, sp/sp²/sp³ hybridisation, the electronic effects that steer reactivity, the reaction intermediates, and the core reaction types and purification methods. Key ideas include Catenation & tetravalency, Hybridisation of carbon, Sigma and pi bonds, IUPAC nomenclature.
What does Class 11 Chemistry Chapter 8 (Organic Chemistry — Basic Principles and Techniques) cover on XamBaaz?+
It has 90 NCERT-based MCQs on "Organic Chemistry — Basic Principles and Techniques": 30 Easy, 30 Medium and 30 Hard. Together they make 9 timed quizzes, and you never get the same set twice. Every question has an instant explanation. They help you prepare for CBSE & Maharashtra HSC Board exams, JEE Main, MHT-CET, JEE Advanced and NEET UG.
Are these "Organic Chemistry — Basic Principles and Techniques" questions free to practise?+
Yes. Sign in with Google to practise "Organic Chemistry — Basic Principles and Techniques" free. Full unlimited access is ₹999/year on a launch offer until 1 December 2026. No chapter is charged separately.
How should I revise "Organic Chemistry — Basic Principles and Techniques" for the exam?+
Start with the Easy quiz to check your basics, then try Medium and Hard to practise applying them. There are 9 timed quizzes on this chapter, so you can come back for a fresh set instead of one you have seen. Read each explanation, retry the questions you miss, and track your accuracy until it stays high.
Are these "Organic Chemistry — Basic Principles and Techniques" MCQs available with answers?+
Yes. 14 sample questions are shown here in full, each with the correct option and a step-by-step "Why" explanation. Sign in free with Google to start practising, with instant scoring.
Is there negative marking in the "Organic Chemistry — Basic Principles and Techniques" quizzes?+
Yes. The timed quizzes use exam-style marking: +4 for a right answer, −1 for a wrong one and 0 for a skip, the same negative marking as JEE Main, JEE Advanced and NEET UG. MHT-CET and CBSE board papers have no negative marking. Our mocks for those are scored their way.
What are the important questions from Organic Chemistry — Basic Principles and Techniques (Class 11 Chemistry)?+
The questions that matter most test Catenation & tetravalency, Hybridisation of carbon, Sigma and pi bonds, IUPAC nomenclature. This page shows 14 solved important MCQs with answers and explanations; all 90 questions on the chapter are available as timed quizzes once you sign in.
Is there an online quiz for Organic Chemistry — Basic Principles and Techniques?+
Yes — Class 11 Chemistry Organic Chemistry — Basic Principles and Techniques has timed online quizzes at Easy, Medium and Hard levels, with instant scoring and a worked explanation on every question. The first quiz on the chapter is free.