Reactivity of Molecules Reaction Mechanism Flashcards by Khristine Tapado

Electronegativity is defined as the power of an atom in a
molecule to
a) Repel electrons towards itself
b) Attract electrons towards itself
c) Expand itself
d) All of the mentioned

b) Attract electrons towards itself

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How does the electronegativiy gets affected with the
negative oxidation state?
a) It decreases
b) It increases
c) It remains constant
d) None of the mentioned

a) It decreases

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The factors on which electronegativity depends upon
a) Valence state of atom
b) Hybridisation
c) Both valence state and hybridisation
d) None of the mentioned

c) Both valence state and hybridisation

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The electronegativity of sp2 hybridised atom will be
a) 3.29
b) 2.48
c) 3.69
d) 2.75

d) 2.75

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Arrange the following groups in the order of decreasing
(+I) effect.
a) C6H5O– > COO– > CR3 > CHR2 > H
b) C6H5O– > H > CR3 > CHR2 > COO–
c) CR3 > C6H5O– > H > COO– > CHR2
d) C6H5O– > COO– > CHR2 > CR3 > H

a) C6H5O– > COO– > CR3 > CHR2 > H

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Which of the following is a permanent electron
displacement effect?
a) Inductomeric
b) Electromeric
c) Inductive
d) All of the mentioned

c) Inductive

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Select the correct statement from the following option
a) When multiple bonds are present between two
different atoms, electromeric shift towards the more
electronegative atom takes place
b) When multiple bonds are present between two similar
atoms, the first possibility is symmetric alkenes or alkynes
c) When multiple bonds are present between two similar
atoms, the second possibility is asymmetric alkenes or
alkynes
d) All of the mentioned

d) All of the mentioned

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Arrange the following groups in the order of decreasing
(-I) effect.
a) CN > F > Br > Cl > COOH > I > H
b) COOH > CN > F > Br > Cl > I > H
c) H > COOH > CN > I > Cl > F > Cl
d) CN > COOH > F > Cl > Br > I > H

d) CN > COOH > F > Cl > Br > I > H

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Which of the following is an application of inductive
effect?
a) Bond length
b) Dipole moment
c) Strength of carboxylic acids
d) All of the mentioned

d) All of the mentioned

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Due to presence of C – X polar bond in alkyl halide,
alkyl halides are
a) More reactive than corresponding alkane
b) Less reactive than corresponding alkane
c) Equally reactive as corresponding alkane
d) None of the mentioned

a) More reactive than corresponding alkane

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Relative basic strength of amines does not depend upon
a) Inductive effect
b) Mesomeric effect
c) Steric effect
d) Stabilisation of cation by hydration

b) Mesomeric effect

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Which of the following is a temporary effect brought
into play at the requirement of attacking reagent?
a) Inductive effect
b) Mesomeric effect
c) Electromeric effect
d) Inductomeric effect

c) Electromeric effect

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Select the correct statement from the following option.
a) Conjugate effect is stronger than (-I) effect
b) Conjugate effect is weaker than (-I) effect
c) Conjugate effect is same as (-I) effect
d) None of the mentioned

a) Conjugate effect is stronger than (-I) effect

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When the complete transfer of π-electrons take place
away from the atom at the requirement of attacking
agent, it is called
a) (-E) effect
b) (+E) effect
c) (-I) effect
d) (+I) effect

b) (+E) effect

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Which of the following is an example of lewis base?
a) ZnCl2
b) BF3
c) NH3
d) FeCl2

c) NH3

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The positively charged and electron deficient
compounds which have a tendency to form a bond by
accepting the electron pair are known as
a) Electrophiles
b) Nucleophiles
c) Homophiles

a) Electrophiles

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Which of the following is an incorrect statement about
the nucleophiles?
a) They are electron rich
b) They possess an empty orbital to receive the electron
pair
c) They attack electron deficient centres
d) Examples are: OH–, NH3, H2O etc

b) They possess an empty orbital to receive the electron
pair

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Lewis acids are the examples of nucleophilic reagents.
a) True
b) False

b) False

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Which of the following is a resonance effect?
a) Inductive effect
b) Electromeric effect
c) Mesomeric effect
d) Inductomeric effect

c) Mesomeric effect

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Which of the following molecule will show highest
dipole moment?
a) CH3Cl
b) CH3Br
c) CH3F
d) CH3I

c) CH3F

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Those groups which are electron repelling and have
lesser electron attracting power than hydrogen show
a) (+E) effect
b) (-E) effect
c) (-I) effect
d) (+I) effect

d) (+I) effect

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In mesomeric effect, the electrons are transferred from
a) A multiple bonds to an atom
b) A multiple bonds to a single covalent bond
c) An atom with a lone pair to the adjacent single covalent
bond
d) All of the mentioned

d) All of the mentioned

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The phenomenon in which 2 or more structures,
involving identical position of atoms can be written for a
particular molecule, is called
a) Conjugation
b) Resonance
c) Hyper conjugation
d) Vibration

b) Resonance

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The resonance energy is defined as a difference in
energy between
a) Two consecutive resonating structures
b) Resonance hybrid and most unstable resonating
structure
c
d) First and last resonating structures

a) Resonating structures have a real existence

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4. Select the incorrect option from the following option. a) Resonating structures have a real existence b) The actual structure lies between various possible resonating structures c) Resonating structures are useful as they allow us to describe molecules d) None of the mentioned

a) Resonating structures have a real existence

6. Which of the following is an application of mesomeric effect? a) Dipole moment b) Strength of acids and bases c) Bond length d) All of the mentioned

d) All of the mentioned

7. Dipole moment of CH3-CH2-Cl > CH2=CH-Cl. a) True b) False

a) True

8. Select the correct statement from the following option. a) Benzene ring has two different types of bond length for single and double bonds b) All the bond length in benzene ring is equal due to hyperconjugation c) All the bond length in benzene ring is equal due to resonance d) All of the mentioned

c) All the bond length in benzene ring is equal due to resonance

9. Greater the number of resonating structures for a given intermediate, a) Less will be its stability b) More will be its stability c) It will not affect its stability d) None of the mentioned

b) More will be its stability

1. Which of the following is known as Baker-Nathan effect? a) Mesomeric effect b) Inductive effect c) Hyperconjugation d) Electromeric effect

c) Hyperconjugation

10. Phenyl group show a) (+M) effect b) (+E) effect c) (+I) effect d) (-M) effect

d) (-M) effect

4. The resonance energy (kCal/mol) of tertiary butyl is a) 9 b) 10 c) 11 d) 12

d) 12

2. Hyperconjugation involves the delocalisation of a) ς bond orbital b) π bond orbital c) Both ς and π bond orbital d) None of the mentioned

a) ς bond orbital

3. Number of hyperconjugation structures in isopropyl radical is a) 3 b) 6 c) 9 d) 12

b) 6

5. Larger the number of hyperconjugation structures, the stability of free radicals will a) Increase b) Decrease c) Remains same d) None of the mentioned

a) Increase

3. The breaking of a covalent bond in such a way that each atom separates with one electron of the shared pair is called a) Homolytic fission b) Heterolytic fission c) Monolytic fission d) Morpholytic fission

a) Homolytic fission

10. Ethene is devoid of any alpha hydrogen so hyperconjugation is not possible. a) True b) False

a) True

6. Which of the following is a consequence of Baker Nathan effect? a) It is helpful in explaining the directive influence of alkyl groups in aromatic alkyl benzene b) It is helpful in explaining the relative stability of alkenes c) It is helpful in explaining the relative stabilities of alkyl carbocations d) All of the mentioned

d) All of the mentioned

7. On increasing the number of α-hydrogens, the number of hyperconjugation structures will a) Decrease b) Increase c) Remains same d) None of the mentioned

b) Increase

8. When the contributing structure contains the same number of two-electron bonds as the normal lewis formula, it will be a) Heterovalent hyperconjugation b) Sacrificial hyperconjugation c) Isovalent hyperconjugation d) All of the mentioned

c) Isovalent hyperconjugation

9. The compound that can be most readily sulphonated is a) Benzene b) Toluene c) Nitrobenzene d) Chlorobenzene

b) Toluene

4. The breaking of a covalent bond in such a way that both the electrons of shared pair are carried away by one of atom is called a) Morpholytic fission b) Monolytic fission c) Heterolytic fission d) Homolytic fission

c) Heterolytic fission

2. Select the incorrect statement from the following option. a) Fission of covalent bond leads to the generation of intermediate organic species b) They are stable and long-lived c) The presence of reactive intermediates is confirmed by their detection by spectroscopic methods d) None of the mentioned

b) They are stable and long-lived

1. A covalent bond between two atoms may be broken in different ways depending upon a) Nature of given organic compound b) Nature of attacking reagent c) Reaction conditions d) All of the mentioned

d) All of the mentioned

8. Which of the following is intermediate organic species based on carbon formed by photolysis? a) Carbenes b) Carbo-cations c) Carbanions d) Free radicals

a) Carbenes

5. Heterolytic fission takes place between two atoms of widely different a) Conductivity b) Viscosity c) Electronegtivity d) All of the mentioned

c) Electronegtivity

6. Select the incorrect statement from the following option. a) Heterolytic fission takes place generally in a polar solvent b) Heterolytic fission takes place usually at higher temperatures c) Cations and anions formed are generally carbon-based d) None of the mentioned

b) Heterolytic fission takes place usually at higher temperatures

7. Which of the following is intermediate organic species based on carbon formed by homolytic fission? a) Carbenes b) Carbo-cations c) Carbanions d) Free radicals

d) Free radicals

9. Triplet carbene is more stable than singlet carbene. a) True b) False

a) True

10. The shape of carbanion is a) Linear b) Trigonal planar c) Pyramidal d) Bent

c) Pyramidal

1. Stability of free radicals can be explained on the basis of a) Inductive effect b) Electromeric effect c) Hyperconjugation d) Mesomeric effect

c) Hyperconjugation

8. The formal charge at the carbocation is equal to a) -1 b) 0 c) +1 d) +2

c) +1

2. The hybridisation of carbocation is a) Sp b) Sp2 c) Sp3 d) Sp3d

b) Sp2

3. Arrange the following carbocations in the order of increasing stability. a) Benzyl > 30 > 20 > 10 b) Benzyl > 10 > 20 > 30 c) 30 > 20 > 10 > Benzyl d) 10 > 20 > 30 > Benzyl

a) Benzyl > 30 > 20 > 10

5. Carbonium ions are the intermediates in which the positive charge is carried by the carbon atom with ___________ electrons in the valence shell. a) 6 b) 5 c) 4 d) 3

a) 6

6. Positive charge of carbocations can be dispersed by a) (+I) effect of alkyl group b) Resonance in allyl or benzyl carbocation c) Hyperconjugation in 10, 20 and 30 carbocations d) All of the mentioned

d) All of the mentioned

4. The shape of carbocation is a) Pyramidal b) Bent c) Linear d) Trigonal planar

d) Trigonal planar

2. The hybridisation of carbanion is a) Sp b) Sp2 c) Sp3 d) Sp3d

c) Sp3

7. Alkyl substitution at the carbon bearing positive charge stabilizes carbocations. a) True b) False

a) True

1. Select the correct statement from the following option. a) Carbanion is the intermediate compound b) In carbanion, central carbon atom carries negative charge c) It possess an unshared pair of electron d) All of the mentioned

d) All of the mentioned

9. The homolytic bond dissociation energy is inversely proportional to the a) Bond length b) Ease of formation c) Dipole moment d) All of the mentioned

b) Ease of formation

10. Which of the following free radical has the maximum ease of formation? a) 10 b) 20 c) 30 d) CH3

c) 30

8. Which of the following carbanion is most stable? a) 10 b) 20 c) 30 d) CH3

d) CH3

5. The structure of carbanion is pyramidal but it undergoes rapid inversion similar to those of amines. a) True b) False

a) True

3. The formal charge at the carbanion is a) +1 b) -1 c) 0 d) +2

b) -1

7. Which of the following carbanion is least stable? a) 10 b) 20 c) 30 d) CH3

c) 30

4. The geometry of carbanion is a) Pyramidal b) Linear c) Tetrahedral d) Trigonal planar

a) Pyramidal

6. Negative charge of carbanion can be dispersed by a) (+I) effect and resonance b) (-I) effect and resonance c) Hyperconjugation d) (+M) effect and resonance

b) (-I) effect and resonance

9. On increasing the number of alkyl groups, the stability of carbanions a) Increases b) Decreases c) Remains same d) None of the mentioned

b) Decreases

10. Due to (+I) effect, the methyl groups are electron accepting in nature. a) True b) False

b) False

1. The atom which defines the structure of a family of organic compounds and their properties is called a) Resonating structure b) Homologous structure c) Functional group d) Nucleophile

c) Functional group

2. The functional group in alkyl halide is a) Hydroxyl group b) Halogen atom c) Inert gas d) All of the mentioned

b) Halogen atom

4. When the nucleophile :OR attacks the RX, the resultant product will be a) R – OH b) ROR c) R:CN d) RNHR

b) ROR

3. The halide ion is an extremely a) Weak base b) Weak acid c) Strong base d) Strong acid

a) Weak base

5. Select the correct statement from the following option. a) SN2 reaction follows second order kinetics b) No intermediate is involved in SN2 mechanism c) SN2 reactions are one-step reaction d) All of the mentioned

d) All of the mentioned

6. The reactivity order of alkyl halides in SN2 is a) CH3 X > 10 > 20 > 30 b) CH3 X > 20 > 10 > 30 c) CH3 X > 30 > 10 > 20 d) CH3 X > 30 > 20 > 10

a) CH3 X > 10 > 20 > 30

7. SN1 reaction involves heterolysis to form the carbocation as an intermediate. a) True b) False

a) True

8. Which step in SN1 reaction is a slow rate determining step? a) Attack of nucleophile b) Formation of a racemic mixture c) Formation of a transition state d) All of the mentioned

c) Formation of a transition state

9. A low concentration of nucleophile favours the a) SN2 reaction b) SN1 reaction c) Both SN1 and SN1 reaction d) None of the mentioned

b) SN1 reaction

10. Which of the following reactions are favoured by polar aprotic solvent? a) SN1 reactions b) SN2 reactions c) Both SN1 and SN1 reactions d) None of the mentioned

b) SN2 reactions

12. Reaction of alcohol with SOCl2 is a) SN1 b) SN2 c) SNAr d) SNi

d) SNi

11. Arrange the following in the decreasing order of leaving group in nucleophilic substitution reaction. a) H– > Cl– > HO– > Br– > CH3COO– b) Cl– > Br– > HO– > H– > CH3COO– c) Cl– > Br– > CH3COO – > HO– > H– d) HO– > CH3COO – > H– > Br– > Cl–

c) Cl– > Br– > CH3COO – > HO– > H–

13. The nucleophilic substitutions do not occur in haloarenes because a) The carbon-halogen bond is much shorter b) The carbon-halogen bond is stronger compared to that in haloalkanes c) The lone pair of electrons on the halogen participates in delocalisation with the π-electrons of benzene ring d) All of the mentioned

d) All of the mentioned

14. Which of the following drastic condition is required for the substitution in haloarenes? a) High temperature b) High pressure c) Strong concentrated reagent d) All of the mentioned

d) All of the mentioned

15. The rate of nucleophilic substitution reactions are higher in the presence of a) Electron withdrawing groups b) Electron releasing groups c) Both electron withdrawing and releasing groups d) None of the mentioned

a) Electron withdrawing groups

1. Which of the following is rate determining step in electrophilic substitution reaction? a) Generation of electrophile b) Attack by an electrophilic reagent on benzene ring c) Formation of product d) All of the mentioned

b) Attack by an electrophilic reagent on benzene ring

2. Which of the following act as a catalysis in the nitration of benzene? a) Conc. HCl b) Dil. HCl c) Conc. H2SO4 d) Dil. H2SO4

c) Conc. H2SO4

3. Fuming sulphuric acid is the solution of _________% SO3 in conc. H2SO4. a) 10 b) 9 c) 8 d) 7

d) 7

4. Which of the following is the necessary condition for desulphonation? a) Remove volatile hydrocarbon by steam distillation b) Low concentration of water c) High concentration of sulphonating agent d) A large excess of fuming sulphuric acid

a) Remove volatile hydrocarbon by steam distillation

5. Which of the following act as electrophile in halogenation? a) Nitronium ion b) Sulphonium ion c) Halonium ion d) Acylium io

c) Halonium ion

6. Aromatic bromination catalyzed by the Lewis acid thalium acetate gives a) Para isomer b) Ortho isomer c) Meta isomer d) Para and ortho isome

a) Para isomer

8. Which of the following is not a product of the reaction of benzene with CH3Cl and AlCl3? a) Toulene b) Isopropyl benzene c) O-xylene d) P-xylene View Answer

b) Isopropyl benzene

7. The reaction in which benzene reacts with alkyl halide in presence of a lewis acid as a catalyst to produce alkylbenzene is known as a) Nitration b) Halogenation c) Friedel-Crafts Acylation d) Friedel-Crafts Alkylation

d) Friedel-Crafts Alkylation

10. How will you convert benzene into n-propyl benzene? a) Friedel-Crafts Alkylation b) Friedel-Crafts Acylation c) Friedel-Crafts Alkylation followed by clemmensen reduction d) Friedel-Crafts Acylation followed by clemmensen reduction

d) Friedel-Crafts Acylation followed by clemmensen reduction

9. The product of Friedel-Crafts Acylation reactions are a) Alkylbenzene b) Alkylamine c) Arylketone d) Halobenzene

c) Arylketone

1. An activating substituent group activates a) Ortho position b) Para position c) Both ortho and para positions d) Meta position

b) Para position

4. Which of the following is meta directing group? a) –NHCOCH3 b) –COOH c) –OH d) –OCH3

b) –COOH

6. Which of the following has the highest activation of benzene ring? a) – NHCOCH3 b) –OH c) –NH2 d) –C6H5

c) –NH2

2. A deactivating substituent group directs a) Ortho position b) Para position c) Both ortho and para positions d) Meta position

d) Meta position

5. The most stable carbonium ion is a) Methyl carbonium ion b) 20 carbonium ion c) 10 carbonium ion d) 30 carbonium ion

d) 30 carbonium ion

3. Which of the following is ortho-para directing group? a) –NHCOCH3 b) –NO2 c) –CN d) –CHO

a) –NHCOCH3

7. HBr reacts fastest with a) 2-methylpropan-2-ol b) Propan-1-ol c) Propan-2-ol d) 2-methylpropan-1-ol

a) 2-methylpropan-2-ol

7. HBr reacts fastest with a) 2-methylpropan-2-ol b) Propan-1-ol c) Propan-2-ol d) 2-methylpropan-1-ol

c) Propan-2-ol

9. In Cannizaro reaction, two molecules of aldehydes are reacted to produce a) Alcohol only b) Carboxylic acid only c) Alcohol and carboxylic acid d) Alcohol, carboxylic acid and ketone

c) Alcohol and carboxylic acid

Reactivity of Molecules Reaction Mechanism Flashcards

(104 cards)