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

Question: Which of the following scientist proposed that a ‘vital force’ was responsible for the formation of organic compounds ?

• a) Berzilius
• b) Berthelot
• c) Wohler
• d) Kolbe

Answer: Berzilius

Question: First organic compound to be synthesised was

• a) urea
• b) cane sugar
• c) methane
• d) acetic acid

Answer: urea

Question: Which of the following organic compound was synthesised by F. Wohler from an inorganic compound?

• a) Urea
• b) Chloroform
• c) Methane
• d) Acetic acid

Answer: Urea

Question: The discovery that shook the belief in the vital force theory was

• a) Wholer’s synthesis of urea from ammonium cyanate
• b) Fermentation of sugars
• c) Synthesis of indigo
• d) Stereoisomerism

Answer: Wholer’s synthesis of urea from ammonium cyanate

Question: In laboratory, first organic compound was synthesised by

• a) Wohler
• b) Kekule
• c) Hennel
• d) Liebig

Answer: Wohler

Question: Who is known as the “Father of Chemistry”?

• a) Lavoisier
• b) Priestley
• c) Faraday
• d) Rutherford

Answer: Lavoisier

Question: The hybridisation of carbon atom in C — C single bond of H₂C = CH — CH = CH₂ is

• a) sp² — sp²
• b) sp³ — sp³
• c) sp² — sp
• d) sp³ — sp

Answer: sp² — sp²

Question:

The state of hybrization of carbons 1, 3 and 5 are in the following sequence

• a) sp, sp³, sp²
• b) sp³, sp², sp
• c) sp², sp, sp³
• d) sp, sp², sp³

Answer: sp, sp³, sp²

Question: The percentage of s- character of the hybrid orbitals in ethane, ethene and ethyne are respectively

• a) 25, 33, 50
• b) 50, 75, 100
• c) 10, 20, 40
• d) 25, 50, 75

Answer: 25, 33, 50

Question:

• a) CH₃CH = CH₂
• b) CH₂ = CHCHO
• c) CH₃CH=CHCOOH
• d) None of these

Answer: CH₃CH = CH₂

Question: 2- Pentene contains

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: Which of the following does not represent the 2 – bromo pentane ?

• a) (ii) and (iii)
• b) (ii), (iii) and (v)
• c) Only (ii)
• d) (iii) and (v)

Answer: (ii) and (iii)

Question: Which of the following correctly represents the expanded form of following organic compound ?

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question:  Structural formula of benzene is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: The successive members in a homologues series differ from each other by ________

• a) – CH₂ unit
• b) – CH₃ unit
• c) – OCH₃ unit
• d) None of these

Answer: – CH₂ unit

Question :

• a) (A) and (D)
• b) (B) and (D)
• c) Only (D)
• d) Only (B)

Answer: (A) and (D)

Question: The correct decreasing order of priority of functional groups is

• a) – COOH, – SO₃H, – COOR, – OH
• b)

  

• c)

  

• d) None of these

Answer: – COOH, – SO₃H, – COOR, – OH

Question: Which of the following is incorrectly matched –

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: The functional group present in organic, acid is –

• a) –COOH
• b) – OH
• c) – CHO
• d) > C = O

Answer: –COOH

Question: Which of these contains the carbonyl group?

• a) all of these
• b) aldehydes
• c) ketones
• d) esters

Answer: all of these

More Questions..........................

Question: Butanone is a four-carbon compound with the functional group –

• a) ketone
• b) carboxylic acid
• c) aldehyde.
• d) alcohol.

Answer: ketone

Question: The functional group present in CH₃COOC₂H₅ is

• a) ester
• b) ketonic
• c) aldehydic
• d) carboxylic

Answer: ester

Question: Which of the following compounds contains 1°, 2°, 3° as well as 4° carbon atoms ?

• a) 2,2,3-trimethyl pentane
• b) 2-methyl pentane
• c) Neopentane
• d) 2,3-dimethyl butane

Answer: 2,2,3-trimethyl pentane

Question: The number of secondary hydrogens in 2, 2-dimethylbutane is

• a) 2
• b) 6
• c) 8
• d) 4

Answer:  2

Question: The compound which has one isopropyl group is

• a) 2- Methypentane
• b) 2, 2, 3- Trimethylpentane
• c) 2, 2 - Dimethylpentane
• d) 2, 2, 3, 3 - Tetramethylpentane

Answer: 2- Methypentane

Question: Which of the following statements is false for isopentane ?

• a) It has a carbon which is not bonded to hydrogen
• b) It has one CH group
• c) It has one CH₂ group
• d) It has three CH₃ groups

Answer:  It has a carbon which is not bonded to hydrogen

Question: The number of primary, secondary and tertiary carbons in 3, 4-dimethylheptane are respectively

• a) 4, 3 and 2
• b) 4, 2 and 3
• c) 2, 3 and 4
• d) 3, 4 and 2

Answer: 4, 3 and 2

Question: The number of primary, secondary, tertiary and quaternary carbons in neopentane are respectively

• a) 4, 0, 0 and 1
• b) 4, 3, 2 and 1
• c) 5, 0, 0 and 1
• d) 4, 0, 1 and 1

Answer: 4, 0, 0 and 1

Question: What is the IUPAC name of t-butyl alcohol

• a) 2–Methyl-propan–2-ol
• b) Propanol-2
• c) Butanol–2
• d) Butanol–1

Answer: 2–Methyl-propan–2-ol

Question: The IUPAC name of CH₃COCH (CH₃)₂ is -

• a) 3-methyl-2-butanone
• b) 4-methylisopropyl ketone
• c) 2-methyl-3-butanone
• d) isopropyl methyl ketone

Answer: 3-methyl-2-butanone

Question:

• a) 2–ethyl–3–methylpentanal
• b) 2, 3–diethylbutanal
• c) 2–sec butylbutanal
• d) 3–methyl–2–ethylpentanal

Answer: 2–ethyl–3–methylpentanal

Question: Which of the following statements is false for isopentane

• a) It has a carbon which is not bonded to hydrogen
• b) It has one CH group
• c) It has one CH₂ group
• d) It has three CH₃ groups

Answer: It has a carbon which is not bonded to hydrogen

Question: The IUPAC name of the compound CH₃OCH₂CH₂CH₂OCH₂CH₃ is

• a) 3-ethoxy-1-methoxypropane
• b) 1-ethoxy-3-methoxypropane
• c) 2, 5-dioxyhexane
• d) ethoxypropane oxymethane

Answer: 3-ethoxy-1-methoxypropane

Question: Which of the following compounds has wrong IUPAC name?

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question:

• a) 3-bromo-1-chlorocyclohexene
• b) 1-bromo-3-chlorocyclohexene
• c) 2-bromo-6-chlorocyclohex-1-ene
• d) 6-bromo-2-chlorocyclohexene

Answer: 3-bromo-1-chlorocyclohexene

Question:

• a) 3-methyl pentan-3-ol
• b) diethylethanol
• c) 1-ethyl-1-methylpropan-1-ol
• d) 2-ethylbutan-2-ol

Answer: 3-methyl pentan-3-ol

Question:

• a) 5–chlorohex–2–ene
• b) 2–chlorohex–5–ene
• c) 1–chloro–1–methylpent–3–ene
• d) 5–chloro–5–methylpent–2–ene

Answer: 5–chlorohex–2–ene

Question:

• a) 2 - phenylbutane
• b) 3 - phenylbutane
• c) 2 - cyclohexylbutane
• d) 3 - cyclohexylbutane

Answer: 2 - phenylbutane

Question:

• a) 5-methyl-3-hexanamine
• b) 2-methyl-4-hexanamine
• c) 2-methyl-4-amino hexane
• d) 5-methyl-3-amino hexane

Answer: 5-methyl-3-hexanamine

Question: Which one of the following is ethyl-4-(dimethyl amino) butanoate ?

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question:

• a) 5 – methyl – 4 – phenyl hexanal
• b) 5 – isopropyl – 5 – phenyl butanal
• c) 2 – methyl – 3 – phenyl hexanal
• d) 4 – benzyl – 5 – methyl hexanal

Answer: 5 – methyl – 4 – phenyl hexanal

Question: IUPAC name of (CH₃)₃ CCl is

• a) 2-chloro-2-methylpropane
• b) 3-chloro butane
• c) 1-butyl chloride
• d) 2-butyl chloride

Answer: 2-chloro-2-methylpropane

Question:

• a) N, N-dimethylcyclopropane carboxamide
• b) N-methylcyclopropanamide'
• c) cyclopropionamide
• d) None of these

Answer: N, N-dimethylcyclopropane carboxamide

Question: Which of the following is a 3-methylbutyl group?

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question:

• a) 3-ethyl-5-methylheptane
• b) 5-ethyl-3-methylheptane
• c) 3,5-diethylhexane
• d) 1,1-diethyl-3-methylpentane

Answer: 3-ethyl-5-methylheptane

Question:

• a) 2,8-dimethyl-4,6-decadiene
• b) 1,5-di-iso-propyl-1,4-hexadiene
• c) 2,8-dimethyl-3,6-decadiene
• d) 1,1,7,7-tetramethyl-2,5-octadiene

Answer: 2,8-dimethyl-4,6-decadiene

Question:

• a) 3-methyl 2-butanone
• b) 2-methyl 3-butanone
• c) isopropyl methyl ketone
• d) methyl isopropyl ketone

Answer: 3-methyl 2-butanone

Question: The IUPAC name of neopentane is

• a) 2, 2-dimethylpropane
• b) 2, 2-dimethylbutane
• c) 2-methylpropane
• d) 2-methylbutane

Answer: 2, 2-dimethylpropane

Question:

• a) 1-Chloro-4-methyl-2-nitrobenzene
• b) 1-Chloro-2-nitro-4-methyl benzene
• c) 2-Chloro-1-nitro-5-methyl benzene
• d) m-Nitro-p-chlorotoluene

Answer: 1-Chloro-4-methyl-2-nitrobenzene

Question:

• a) 2 – bromo – 4 – ethylbenzene carboxylic acid
• b) 6 – bromo – 4 – ethylbenzene carboxylic acid
• c) Ortho – bromo – paraethyl benzoic acid
• d) 4 – bromo – 3 – ethyl benzoic acid

Answer: 2 – bromo – 4 – ethylbenzene carboxylic acid

Question: Total number of structural isomers possible for C₃H₆ are :

• a) 2
• b) 4
• c) 1
• d) 3

Answer: 2

Question: An aromatic compound of formula C₇H₇Cl has in all ..... isomers

• a) 4
• b) 5
• c) 2
• d) 3

Answer: 4

Question: CH₃CH₂OH and CH₃OCH₃ are the examples of

• a) functional isomerism
• b) metamerism
• c) chain isomerism
• d) position isomerism

Answer: functional isomerism

Question: Which organic structure among the following is not an isomer of the compound CH₃–CO–CH₂CH₂CH₂CH₃ ?

• a) CH₃CH = CHCH₂CH₂CHO
• b) (CH₃)₂CH–CO–CH₂CH₃
• c) Both
• d) None of these

Answer: CH₃CH = CHCH₂CH₂CHO

Question: The least number of carbon atoms in alkane showing isomerism is

• a) 4
• b) 1
• c) 3
• d) 2

Answer: 4

Question: The number of possible alkynes with molecular formula C₅H₈ is

• a) 3
• b) 5
• c) 2
• d) 4

Answer: 3

Question: The total number of isomers for C₄H₈ is

• a) 6
• b) 8
• c) 5
• d) 7

Answer: 6

Question:  Which of the following compounds is isomeric with 2, 2, 4, 4- tetramethylhexane?

• a) 4-isopropylheptane
• b) 3-ethyl -2, 2- dimethylpentane
• c) 4-ethyl-3-methyl-4-n propyloctane
• d) 4, 4-diethyl-3-methylheptane

Answer: 4-isopropylheptane

Question: Which are isomers ?

• a) ethyl alcohol and dimethyl ether
• b) acetone and acetaldehyde
• c) propionic acid and propanone
• d) methyl alcohol and dimethyl ether

Answer: ethyl alcohol and dimethyl ether

Question: Methoxyethane and propanol are the examples of isomerism of the type

• a) functional
• b) structural
• c) position
• d) tautomerism

Answer: functional

Question: Isomers of propionic acid are

• a) HCOOC₂H₅ and CH₃COOCH₃
• b) HCOOC₂H₅ and C₃H₇COOH
• c) CH₃COOCH₃ and C₃H₇OH
• d) None of these

Answer: HCOOC₂H₅ and CH₃COOCH₃

Question:

• a) Functional
• b) Linkage
• c) Position
• d) Tautomerism

Answer: Functional

Question: A functional isomer of 1-butyne is

• a) 1, 3-butadiene
• b) 1-butene
• c) 2-butyne
• d) 2-butene

Answer: 1, 3-butadiene

Question: In which of the following, functional group isomerism is not possible?

• a) Alkyl halides
• b) Alcohols
• c) Aldehydes
• d) Cyanides

Answer: Alkyl halides

Question: The compounds CH₃CH == CHCH₃ and CH₃CH₂CH == CH₂

• a) are position isomers
• b) are tautomers
• c) exist together in dynamic equilibrium
• d) None of these

Answer: are position isomers

Question: Heterolytic fission of a covalent bond in organic molecules gives

• a) cations and anions
• b) only anions
• c) free radicals
• d) only cations

Answer: cations and anions

Question: Which of the following statements is not correct ?

• a)

  

• b) Carbocation posses sextet of electrons.
• c) Carbocations have trigonal planar shape
• d) Carbocations are formed by heterolytic cleavage

Answer:

Question: Heterolytic fission of C – Br bond results in the formation of

• a) carbocation
• b) free radical
• c) carbanion
• d) None of these

Answer: carbocation

Question: Which of the following carbocations is least stable?

• a) Methyl
• b)

  

• c)

  

• d) pri-Alkyl

Answer:  Methyl

Question: Which of the following ions is most stable ?

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question:

• a) III > I > II
• b) II > III > I
• c) III > II > I
• d) I > II > III

Answer: III > I > II

Question:  Select the most stable carbocation amongst the following

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: The most stable carbonium ion among the following is

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: The organic reaction which proceed through heterolytic bond cleavage are called ________

• a) Both
• b) ionic
• c) polar
• d) None of these

Answer: Both

Question:

• a)

  

• b) it is non-planar
• c) an electrophile can attack on its C⁺
• d) it does not undergo hydrolysis

Answer: 

Question: The shape of methyl carbanion is similar to that of –

• a) NH₃
• b) methyl carbocation
• c) BF₃
• d) methyl free radical

Answer:  NH₃

Question:

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: The homolytic fission of a covalent bond liberates

• a) Free radicals
• b) Carbonium ions
• c) Carbanions
• d) Carbenes

Answer: Free radicals

Question: Homolytic fission of C–C bond in ethane gives an intermediate in which carbon is

• a) sp²-hybridised
• b) sp²d-hybridised
• c) sp-hybridised
• d) sp³-hybridised

Answer:  sp²-hybridised