JEE Chemistry Organic Chemistry Some Basic Principles and Techniques MCQs Set 66

Chemistry Objective Questions and Answers: Organic Chemistry Some Basic Principles and Techniques

Explore reliable objective questions for Organic Chemistry Some Basic Principles and Techniques tailored for JEE learners. Utilizing these Chemistry multiple-choice formats ensures thorough preparation and strengthens problem-solving speed for upcoming school assessments.

Download Organic Chemistry Some Basic Principles and Techniques MCQs with Answers

Access the complete set of multiple-choice questions for Organic Chemistry Some Basic Principles and Techniques below. This focused format allows students to isolate specific topics for thorough review and uninterrupted practice alongside official JEE textbooks.

Multiple Choice Questions

Question 1: Carbon and hydrogen are estimated in organic compounds by:
(a) Kjeldahl's method
(b) Dumas' method
(c) Liebig's method
(d) Carius method
Show Answer & Explanation

Answer: (c) Liebig's method

Explanation:
1. In Liebig's method the compound is burnt in oxygen, CO2 is absorbed in KOH and H2O in anhydrous CaCl2.
2. Answer: (c)

Teacher's Note:
1. Work through each option against the rule or structure involved before choosing. Remember the exceptions your textbook lists.

Question 2: Lassaigne's test for the detection of nitrogen will fail in the case of:
(a) NH2CONH2
(b) NH2CONHNH2·HCl
(c) NH2NH2·HCl
(d) C6H5NHNH2·2HCl
Show Answer & Explanation

Answer: (c) NH2NH2·HCl

Explanation:
1. Sodium cyanide must form during fusion, which needs carbon in the compound.
2. Hydrazine hydrochloride has no carbon, so the test fails.
3. Answer: (c)

Teacher's Note:
1. Work through each option against the rule or structure involved before choosing. Remember the exceptions your textbook lists.

Question 3: During Lassaigne's test, when N and S are both present in an organic compound they change into:
(a) Na2S and NaCN
(b) NaSCN
(c) Na2SO4 and NaCN
(d) Na2S and NaCNO
Show Answer & Explanation

Answer: (b) NaSCN

Explanation:
1. When both are present, sodium thiocyanate NaSCN forms, which gives blood red colour with Fe3+.
2. Answer: (b)

Teacher's Note:
1. Work through each option against the rule or structure involved before choosing. Remember the exceptions your textbook lists.

Question 4: The purpose of boiling the sodium extract with conc. HNO3 before testing for halogens is:
(a) To make the solution acidic
(b) To make the solution clear
(c) To convert Fe2+ to Fe3+
(d) To convert NaCN to HCN and Na2S to H2S so that they do not interfere with AgNO3
Show Answer & Explanation

Answer: (d) To convert NaCN to HCN and Na2S to H2S so that they do not interfere with AgNO3

Explanation:
1. CN- and S2- would also give precipitates with Ag+.
2. Boiling with HNO3 expels them as HCN and H2S.
3. Answer: (d)

Teacher's Note:
1. Work through each option against the rule or structure involved before choosing. Remember the exceptions your textbook lists.

Question 5: In Dumas' and Kjeldahl's methods respectively, nitrogen is estimated as:
(a) N2, NH3
(b) NH3, N2
(c) NO2, NH3
(d) N2, N2
Show Answer & Explanation

Answer: (a) N2, NH3

Explanation:
1. Dumas' method collects free nitrogen gas.
2. Kjeldahl's method converts nitrogen to ammonium sulphate and then liberates NH3.
3. Answer: (a)

Teacher's Note:
1. Work through each option against the rule or structure involved before choosing. Remember the exceptions your textbook lists.

Question 6: When N and S are both present in an organic compound, the sodium extract with FeCl3 gives:
(a) Green colour
(b) Blue colour
(c) Yellow colour
(d) Blood red colour
Show Answer & Explanation

Answer: (d) Blood red colour

Explanation:
1. NaSCN is formed, and SCN- with Fe3+ gives blood red [Fe(SCN)]2+.
2. Answer: (d)

Teacher's Note:
1. Work through each option against the rule or structure involved before choosing. Remember the exceptions your textbook lists.

Question 7: In Lassaigne's test, the organic compound is fused with sodium metal in order to:
(a) Hydrolyse the compound
(b) Form a sodium derivative
(c) Burn the compound
(d) Convert nitrogen, sulphur or halogen present into soluble ionic sodium salts
Show Answer & Explanation

Answer: (d) Convert nitrogen, sulphur or halogen present into soluble ionic sodium salts

Explanation:
1. The covalently bound elements are converted into ionic NaCN, Na2S and NaX, which can be tested in aqueous extract.
2. Answer: (d)

Teacher's Note:
1. Work through each option against the rule or structure involved before choosing. Remember the exceptions your textbook lists.

Question 8: Aniline is separated from an aniline-water mixture by:
(a) Simple distillation
(b) Fractional distillation
(c) Steam distillation
(d) Distillation under reduced pressure
Show Answer & Explanation

Answer: (c) Steam distillation

Explanation:
1. Aniline is steam volatile and immiscible with water, so it is purified by steam distillation.
2. Answer: (c)

Teacher's Note:
1. Work through each option against the rule or structure involved before choosing. Remember the exceptions your textbook lists.

Question 9: o-Nitrophenol and p-nitrophenol are separated by:
(a) Steam distillation
(b) Simple distillation
(c) Fractional distillation
(d) Distillation under reduced pressure
Show Answer & Explanation

Answer: (a) Steam distillation

Explanation:
1. o-Nitrophenol has intramolecular hydrogen bonding and is steam volatile.
2. p-Nitrophenol is intermolecularly hydrogen bonded and is not volatile in steam.
3. Answer: (a)

Teacher's Note:
1. Work through each option against the rule or structure involved before choosing. Remember the exceptions your textbook lists.

Question 10: Glycerol is separated from spent lye by:
(a) Steam distillation
(b) Vacuum distillation
(c) Sublimation
(d) Simple distillation
Show Answer & Explanation

Answer: (b) Vacuum distillation

Explanation:
1. Glycerol decomposes at its normal boiling point, so it is distilled under reduced pressure.
2. Answer: (b)

Teacher's Note:
1. Work through each option against the rule or structure involved before choosing. Remember the exceptions your textbook lists.

Question 11: Two volatile and miscible liquids can be separated by fractional distillation into pure components when:
(a) They have low boiling points
(b) The difference in boiling points is large
(c) The boiling points of the two liquids are close to each other
(d) They do not form an azeotropic mixture
Show Answer & Explanation

Answer: (d) They do not form an azeotropic mixture

Explanation:
1. Fractional distillation works when the liquids do not form an azeotrope, since an azeotrope boils at a constant composition.
2. A large difference would allow simple distillation, but the key idea is the absence of azeotrope formation.
3. Answer: (d)

Teacher's Note:
1. Work through each option against the rule or structure involved before choosing. Remember the exceptions your textbook lists.

Question 12: A mixture contains four solid organic compounds A, B, C and D. On heating, only C changes from solid to vapour directly. C can be separated from the rest by:
(a) Distillation
(b) Sublimation
(c) Fractional distillation
(d) Crystallisation
Show Answer & Explanation

Answer: (b) Sublimation

Explanation:
1. A solid that passes directly to vapour on heating is separated by sublimation.
2. Answer: (b)

Teacher's Note:
1. Work through each option against the rule or structure involved before choosing. Remember the exceptions your textbook lists.

Question 13: Simple distillation can be used to separate:
(a) Chloroform and aniline
(b) Ether and toluene
(c) Hexane and toluene
(d) All of these
Show Answer & Explanation

Answer: (d) All of these

Explanation:
1. Simple distillation separates liquids whose boiling points differ by a large margin (about 40 K or more).
2. Chloroform (334 K) and aniline (457 K), ether (308 K) and toluene (384 K), hexane (342 K) and toluene (384 K) all qualify.
3. Answer: (d)

Teacher's Note:
1. Work through each option against the rule or structure involved before choosing. Remember the exceptions your textbook lists.

Question 14: A mixture of acetone and methyl alcohol can be separated by:
(a) Simple distillation
(b) Fractional distillation
(c) Sublimation
(d) Chromatography
Show Answer & Explanation

Answer: (b) Fractional distillation

Explanation:
1. Their boiling points are close (329 K and 338 K), so fractional distillation is used.
2. Answer: (b)

Teacher's Note:
1. Work through each option against the rule or structure involved before choosing. Remember the exceptions your textbook lists.

Question 15: The principle involved in paper chromatography is:
(a) Adsorption
(b) Partition
(c) Solubility
(d) Volatility
Show Answer & Explanation

Answer: (b) Partition

Explanation:
1. Paper chromatography is partition chromatography, with water held in the cellulose as the stationary phase.
2. Answer: (b)

Teacher's Note:
1. Work through each option against the rule or structure involved before choosing. Remember the exceptions your textbook lists.

Free study material for Chemistry

Multiple Choice Questions (MCQs) for JEE Chemistry Organic Chemistry Some Basic Principles and Techniques

Download Multiple Choice Questions: Organic Chemistry Some Basic Principles and Techniques (JEE Chemistry)

Explore reliable practice questions for Organic Chemistry Some Basic Principles and Techniques tailored for JEE Chemistry learners. Use these multiple-choice formats to evaluate preparedness and strengthen problem-solving skills.

Concept Clarification for Organic Chemistry Some Basic Principles and Techniques

Built using the official NCERT book for JEE, these Chemistry objective sets provide reliable academic guidance. Pair your practice with our recommended NCERT solutions to master optimal problem-solving approaches.

Additional Study Resources for JEE Chemistry

Explore our broader library of printable assignments, chapter notes, and mock tests designed to support continuous revision and secure higher marks in JEE assessments.

FAQs

Where can I access latest JEE Chemistry Organic Chemistry Some Basic Principles and Techniques MCQs Set 66?

You can get most exhaustive JEE Chemistry Organic Chemistry Some Basic Principles and Techniques MCQs Set 66 for free on StudiesToday.com. These MCQs for JEE Chemistry are updated for the 2026-27 academic session as per JEE examination standards.

Are Assertion-Reasoning and Case-Study MCQs included in the Chemistry JEE material?

Yes, our JEE Chemistry Organic Chemistry Some Basic Principles and Techniques MCQs Set 66 include the latest type of questions, such as Assertion-Reasoning and Case-based MCQs. 50% of the JEE paper is now competency-based.

How do practicing Chemistry MCQs help in scoring full marks in JEE exams?

By solving our JEE Chemistry Organic Chemistry Some Basic Principles and Techniques MCQs Set 66, JEE students can improve their accuracy and speed which is important as objective questions provide a chance to secure 100% marks in the Chemistry.

Do you provide answers and explanations for JEE Chemistry Organic Chemistry Some Basic Principles and Techniques MCQs Set 66?

Yes, Chemistry MCQs for JEE have answer key and brief explanations to help students understand logic behind the correct option as its important for 2026 competency-focused JEE exams.

Can I practice these Chemistry JEE MCQs online?

Yes, you can also access online interactive tests for JEE Chemistry Organic Chemistry Some Basic Principles and Techniques MCQs Set 66 on StudiesToday.com as they provide instant answers and score to help you track your progress in Chemistry.