Organic Chemistry – Some Basic Principles and Techniques

The correct IUPAC name of the following compound is : [figure]

1. 3-ethyl-5-methylheptane
2. 3-methyl-5-ethylheptane
3. 2,4-diethylhexane
4. 3,5-diethylhexane

The following carbocation is stabilized by the interaction of the empty p orbital with [figure]

1. empty * and empty * orbitals
2. filled and filled orbitals
3. empty and empty * orbitals
4. empty * and filled orbitals

Arrange the following compounds in the increasing order of polarity A. CH3CH2OCH2CH3 B. CH3CH2OH C. CH3COCH3 D. CH3COOH Choose the correct answer from the options given below.

1. A < C < B < D
2. A < B < C < D
3. C < A < D < B
4. C < A < B < D

Among the given compounds I-III, the correct order of bond dissociation energy of C-H bond marked with * is : [figure]

1. III > II > I
2. II > III > I
3. II > I > III
4. I > II > III

The most stable carbocation among the following is :

1. [figure]
2. [figure]
3. [figure]
4. [figure]

A compound with a molecular formula of C6H14 has two tertiary carbons. Its IUPAC name is :

1. n-hexane
2. 2-methylpentane
3. 2,3-dimethylbutane
4. 2,2-dimethylbutane

The correct IUPAC name of the compound [figure] is :

1. 4-ethyl-1-fluoro-2-nitrobenzene
2. 4-ethyl-1-fluoro-6-nitrobenzene
3. 3-ethyl-6-fluoro-1-nitrobenzene
4. 1-ethyl-4-fluoro-3-nitrobenzene

Methyl group attached to a positively charged carbon atom stabilizes the carbocation due to

1. -I inductive effect
2. electromeric effect
3. hyperconjugation
4. mesomeric effect

The number of bonds, bonds and lone pair of electrons in pyridine, respectively are:

1. 12, 3, 0
2. 11, 3, 1
3. 12, 2, 1
4. 11, 2, 0

Consider the following compounds/species: [figure] The number of compounds/species which obey Hückel's rule is .

1. 6
2. 2
3. 5
4. 4

Which compound amongst the following is not an aromatic compound?

1. [figure]
2. [figure]
3. [figure]
4. [figure]

The correct IUPAC name of the following compound is [figure]

1. 1-bromo-5-chloro-4-methylhexan-3-ol
2. 6-bromo-2-chloro-4-methylhexan-4-ol
3. 1-bromo-4-methyl-5-chlorohexan-3-ol
4. 6-bromo-4-methyl-2-chlorohexan-4-ol

What is the hybridization shown by C1 and C2 carbons, respectively in the given compound? OHC- 1CH=CH- 2CH2COOCH3

1. sp3 and sp3
2. sp2 and sp3
3. sp2 and sp2
4. sp3 and sp2

Which of the following is the most stable carbocation?

1. [figure]
2. [figure]
3. [figure]
4. [figure]

The correct structure of 2, 6-dimethyl-dec-4-ene is

1. [figure]
2. [figure]
3. [figure]
4. [figure]

A tertiary butyl carbocation is more stable than a secondary butyl carbocation because of which of the following?

1. +R effect of -CH3 groups
2. -R effect of -CH3 groups
3. Hyperconjugation
4. -I effect of -CH3 groups

The number of sigma ( ) and pi ( ) bonds in pent-3-en-1-yne is -

1. 11 bonds and 2 bonds
2. 13 bonds and no bonds
3. 10 bonds and 3 bonds
4. 8 bonds and 5 bonds

Which of the following is correct with respect to -I effect of the substituents? (R = alkyl)

1. -NH2 < -OR < -F
2. -NR2 < -OR < -F
3. -NH2 > -OR > -F
4. -NR2 > -OR > -F

Which of the following carbocations is expected to be most stable?

1. [figure]
2. [figure]
3. [figure]
4. [figure]

Which of the following molecules represents the order of hybridisation sp2, sp2, sp, sp from left to right atoms?

1. HC C - C CH
2. CH2 = CH - C CH
3. CH2 = CH - CH = CH2
4. CH3 - CH = CH - CH3

The correct statement regarding electrophile is

1. electrophile is a negatively charged species and form a bond by accepting a pair of electrons from another electrophile
2. electrophiles are generally neutral species and can form a bond by accepting a pair of electrons from a nucleophile
3. electrophile can be either neutral or positively charged species and can form a bond by accepting a pair of electrons from a nucleophile
4. electrophile is a negatively charged species and can form a bond by accepting a pair of electrons from a nucleophile.

The IUPAC name of the compound [figure]

1. 5-formylhex-2-en-3-one
2. 5-methyl-4-oxohex-2-en-5-al
3. 3-keto-2-methylhex-5-enal
4. 3-keto-2-methylhex-4-enal

Which one is the correct order of acidity?

1. CH CH > CH3-C CH > CH2=CH2 > CH3-CH3
2. CH CH > CH2=CH2 > CH3-C CH > CH3-CH3
3. CH3-CH3 > CH2=CH2 > CH3-C CH > CH CH
4. CH2=CH2 > CH3-CH=CH2 > CH3-C CH > CH CH

For the following reactions : (A) CH3CH2CH2Br + KOH CH3CH=CH2 + KBr + H2O (B) [figure] (C) [figure] Which of the following statements is correct?

1. (A) is elimination, (B) and (C) are substitution reactions.
2. (A) is substitution, (B) and (C) are addition reactions.
3. (A) and (B) are elimination reactions and (C) is addition reaction.
4. (A) is elimination, (B) is substitution and (C) is addition reaction.

The pair of electrons in the given carbanion, CH3C C-, is present in which of the following orbitals?

1. sp2
2. sp
3. 2p
4. sp3

In which of the following molecules, atoms are coplanar?

1. [figure]
2. [figure]
3. [figure]
4. [figure]

In pyrrole the electron density is maximum on [figure]

1. 2 and 3
2. 3 and 4
3. 2 and 4
4. 2 and 5

Which of the following statements is not correct for a nucleophile?

1. Ammonia is a nucleophile.
2. Nucleophiles attack low e- density sites.
3. Nucleophiles are not electron seeking.
4. Nucleophile is a Lewis acid.

The total number of π-bond electrons in the following structure is [figure]

1. 12
2. 16
3. 4
4. 8

Which of the following is the most correct electron displacement for a nucleophilic reaction to take place?

1. [figure]
2. [figure]
3. [figure]
4. [figure]