MCQ of Organic Chemistry; Some Basic Principles and Techniques, Chapter 12, Chemistry, Class 11
Question 1: How many σ and π bonds are present in CH2=CH—CH=CH—CH3
- 9σ, 4π
- 12σ, 2π
- 12σ, 6π
- 10σ, 3π
Answer: B (12σ, 2π)
Question 2: Which of the following represents the given sequence of hybridisation of carbon atoms from left to right sp2, sp2, sp , sp
- H2C = CH—C ≡ CH
- HC ≡ C—CH = CH2
- H3C— CH= CH — CH3
- H2C = CH— CH = CH2
Answer: A ( H2C = CH—C ≡ CH)
Question 3: How many primary, secondary, tertiary and quaternary carbon atoms are present in the following compound?
- One primary, two secondary and one tertiary
- Five primary, three secondary
- Five primary, one secondary, one tertiary and one quaternary
- Four primary, two secondary and two quaternary
Answer: C ( Five primary, one secondary, one tertiary and one quaternary )
Question 4: The IUPAC name of the compound having formula
Answer: C (3,3-dimethylpent-1-ene)
Question 5: Which of the foll0wing compounds is not correctly matched with its IUPAC name?
- CH3CH2CH2COOCH2CH3 ; Ethyl butanoate
- ; 3-Methylbutanal
- ; 2-Methylpentan-3-one
- ; 2-Methylbutan-3-ol
Answer: D (2-Methylbutan-3-ol)
Question 6: 1-Butene and cyclobutane show
- Position isomerism
- Ring chain isomerism
- Functional isomerism
Answer: B (Ring chain isomerism)
Question 7: The IUPAC name of the compound shown below is
Answer: C ( 3-bromo-1-chlorocyclohexene )
Question 8: Which of the following is an isomer of ethanol?
Answer: D (Dimethylether)
Question 9: Which of the following compound is isomeric with 2,2,4,4-tetramethylhexane?
Answer: B (4-isopropylheptane)
Question 10: Which of the following intermediate contain three pairs of electron in its valence shell?
- Free radical
- Both (A) and (B)
Answer: A (Carbocation)
You may also read MCQ of Basic Concepts of Chemistry, MCQ of Structure of Atom, MCQ of Classification of Elements and Periodicity in Properties, MCQ of Chemical Bonding and Molecular Structure, MCQ of States of Matter, MCQ of Redox Reactions, MCQ of Hydrogen for better understanding of the chapters.
Question 11: Inductive effect involves
- Displacement of σ electrons resulting in polarisation
- Displacement of π electrons resulting in polarisation
- Delocalisation of σ electrons
- Delocalisation of π electrons
Answer: A ( Displacement of σ electrons resulting in polarisation )
Question 12: Find out the incorrect statement about resonance?
- Resonance structure should have equal energy
- In resonance structure, constituent atoms must be in the same position
- In resonance structure, there should not be same number of electron pairs
- Resonance structure should differ only in the location of electrons around the constituent atoms
Answer: C ( In resonance structure, there should not be same number of electron pairs )
Question 13: Which of the following ions is most stabilized?
Answer: B (Phenoxide)
Question 14: Hyperconjugation is a
- σ-π conjugation
- Noticed due to delocalisation of σ and π bonds
- No bond resonance
- All of the above
Answer: D (All of the above)
Question 15: Stability of iso-butylene can be explained by
- Inductive effect
- Mesomeric effect
- Hyperconjugation effect
- Steric effect
Answer: C (Hyperconjugation effect)
Question 16: Stability of alkyl carbocation can be explained by
- Inductive effect only
- Hyperconjugation effect oly
- Both inductive and hyperconjugation effect
- Electromeric effect only
Answer: C ( Both inductive and hyperconjugation effect )
Question 17: Which of the following statement is not true about carbocation?
- Stability of carbocation increases with increase in s character of orbital
- The electron withdrawing groups –NO2, –CN, >C=O increases the stability of carboanions
- Order of stability of carbocation is 3° > 2° > 1°
- The negatively charged carbon is sp3 hybridised and pyramidal.
Answer: C ( Order of stability of carbocation is 3° > 2° > 1° )
Question 18: Free radicals can underogo
- Rearrangement to a more stable free radical
- Decomposition to give another free radical
- Combination with other free radical
- All are correct
Answer: D (All are correct)
Question 19: Which of the following is characteristic feature of free radical?
- It has a positive charge
- It has a negative charge
- It has all paired electrons
- It has an unpaired electrons
Answer: D (It has an unpaired electron)
Question 20: Which of the following is a false statement?
- Free radicals, carbonium ions or carbanions are reaction intermediates
- Reaction between methane and chlorine in presence of sunlight proceeds via free radical
- The electronegative atom in the carbon chain produces +I effect
- Homolytic fission of C—C bonds give free radical
Answer: C (The electronegative atom in the carbon chain produces +I effect)
Question 21: In which of the following, functional group isomerism is not possible?
- Alkyl halides
Answer: C (Alkyl halides)
Question 22: The correct statement regarding electrophile is
- Electrophile is a negatively charged species and can form a bond by accepting a pair of electrons from another electrophile
- Electrophiles are generally neutral species and can form a bond by accepting a pair of electrons from a nucleophile
- Electrophile can be either neutral or positively charged species and can form a pair of electrons from a nucleophile
- Electrophile is a negatively charged species and can form a bond be accepting a pair of electrons from a nucleophile
Answer: C ( Electrophile can be either neutral or positively charged species and can form a pair of electrons from a nucleophile )
Question 23: Inductive effect of which atom is taken as zero to compare inductive effect of other atoms?
Answer: A (Hydrogen)
Question 24: Which of the following is an electrophilic reagent?
Answer: D (NO2+)
Question 25: Those substances can be sparated by steam distillation are
- Steam volatile and insoluble in water
- Steam volatile and soluble in water
- Steam volatile and sparingly soluble in water
- In liquid form in steam and solid form in water
Answer: A ( Steam volatile and insoluble in water )
Question 26: Which of the following compound would you expect to be strongest?
Answer: D (F-CH2COOH)
Question 27: The number of structural and configurational isomers of a bromo compound, C5H9Br formed by the addition of HBr to 2-Pentyne respectively are
- 1 and 2
- 2 and 4
- 4 and 2
- 2 and 1
Answer: B (2 and 4)
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