Explore topic-wise MCQs in Engineering Chemistry.

This section includes 33 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering Chemistry knowledge and support exam preparation. Choose a topic below to get started.

1.

What will be the correct order of SN2/E2 ratio for the %yield of the product of the following halide?

A. III > IV > II > I
B. III > II > IV > I
C. I > III > IV > II
D. II > I > III > IV
Answer» B. III > II > IV > I
Discussion
2.

Which configuration will be adopted by X and Y respectively?

A. R, R
B. R, S
C. S, S
D. S, R
Answer» C. S, S
Discussion
3.

Which statement is incorrect about the following reaction?

A. The rate of these reaction depends on both [R—I] and [131I-]
B. Loss of optical activity was twice as fast as the gain of radioactivity
C. Each molecule undergoing substitution suffers Inversion of configuration
D. The Final solution has radioactive iodine only
Answer» E.
Discussion
4.

SN1 reaction undergoes through a carbocation intermediate as follows: [R = t-Bu, iso-Pr, Et, Me] (X = Cl, Br, I)The correct statements are:I. The decreasing order of rate of SN1reaction is t-BuX > iso-PrX > EtX > MeXII. The decreasing order of ionization energy is MeX > EtX > iso-PrX > t-BuXIII. The decreasing order of energy of activation is t-BuX > iso-PrX > EtX > MeX

A. I & II are correct
B. I & III are correct
C. II and III are correct
D. I, II & III are correct
Answer» B. I & III are correct
Discussion
5.

Which of the following reaction will go faster if the concentration of the nucleophile is raised?

A. I and III
B. II and IV
C. I and II
D. I, II and IV
Answer» D. I, II and IV
Discussion
6.

Which of the following compound shows the correct decreasing order of solvolysis with aqueous ethanol? The correct choice is:

A. III > II > I > IV
B. III > II > IV > I
C. II > III > IV > I
D. III > I > IV > II
Answer» C. II > III > IV > I
Discussion
7.

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
Answer» B. Electron releasing groups
Discussion
8.

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
Answer» E.
Discussion
9.

Reaction of alcohol with SOCl2 is ___________

A. SN1
B. SN2
C. SNAr
D. SNi
Answer» E.
Discussion
10.

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–
Answer» D. HO– > CH3COO – > H– > Br– > Cl–
Discussion
11.

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
Answer» C. Both SN1 and SN1 reactions
Discussion
12.

A low concentration of nucleophile favours the ___________

A. SN2 reaction
B. SN1 reaction
C. Both SN1 and SN1 reaction
D. None of the mentioned
Answer» C. Both SN1 and SN1 reaction
Discussion
13.

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
Answer» D. All of the mentioned
Discussion
14.

SN1 reaction involves heterolysis to form the carbocation as an intermediate.

A. True
B. False
Answer» B. False
Discussion
15.

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
Answer» B. CH3 X > 20 > 10 > 30
Discussion
16.

When the nucleophile :OR attacks the RX, the resultant product will be ___________

A. R – OH
B. ROR
C. R:CN
D. RNHR
Answer» C. R:CN
Discussion
17.

The halide ion is an extremely ___________

A. Weak base
B. Weak acid
C. Strong base
D. Strong acid
Answer» B. Weak acid
Discussion
18.

The functional group in alkyl halide is ___________

A. Hydroxyl group
B. Halogen atom
C. Inert gas
D. All of the mentioned
Answer» C. Inert gas
Discussion
19.

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
Answer» D. Nucleophile
Discussion
20.

WHICH_OF_THE_FOLLOWING_REACTIONS_ARE_FAVOURED_BY_POLAR_APROTIC_SOLVENT??$

A. S<sub>N</sub>1 reactions
B. S<sub>N</sub>2 reactions
C. Both S<sub>N</sub>1 and S<sub>N</sub>1 reactions
D. None of the mentioned
Answer» C. Both S<sub>N</sub>1 and S<sub>N</sub>1 reactions
Discussion
21.

A_LOW_CONCENTRATION_OF_NUCLEOPHILE_FAVOURS_THE?$

A. S<sub>N</sub>2 reaction
B. S<sub>N</sub>1 reaction
C. Both S<sub>N</sub>1 and S<sub>N</sub>1 reaction
D. None of the mentioned
Answer» C. Both S<sub>N</sub>1 and S<sub>N</sub>1 reaction
Discussion
22.

Reaction of alcohol with SOCl2 is$

A. S<sub>N</sub>1
B. S<sub>N</sub>2
C. S<sub>N</sub>Ar
D. S<sub>N</sub>i
Answer» E.
Discussion
23.

Arrange the following in the decreasing order of leaving group in nucleophilic substitution reaction.
A. H<sup>–</sup> > Cl<sup>–</sup> > HO<sup>–</sup> > Br<sup>–</sup> > CH<sub>3</sub>COO<sup>–</sup>
B. Cl<sup>–</sup> > Br<sup>–</sup> > HO<sup>–</sup> > H<sup>–</sup> > CH<sub>3</sub>COO<sup>–</sup>
C. Cl<sup>–</sup> > Br<sup>–</sup> > CH<sub>3</sub>COO <sup>–</sup> > HO<sup>–</sup> > H<sup>–</sup>
D. HO<sup>–</sup> > CH<sub>3</sub>COO <sup>–</sup> > H<sup>–</sup> > Br<sup>–</sup> > Cl<sup>–</sup>
Answer» D. HO<sup>‚Äö√Ñ√∂‚àö√ë‚àö¬®</sup> > CH<sub>3</sub>COO <sup>‚Äö√Ñ√∂‚àö√ë‚àö¬®</sup> > H<sup>‚Äö√Ñ√∂‚àö√ë‚àö¬®</sup> > Br<sup>‚Äö√Ñ√∂‚àö√ë‚àö¬®</sup> > Cl<sup>‚Äö√Ñ√∂‚àö√ë‚àö¬®</sup>
Discussion
24.

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
Answer» B. Electron releasing groups
Discussion
25.

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
Answer» E.
Discussion
26.

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
Answer» E.
Discussion
27.

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
Answer» D. All of the mentioned
Discussion
28.

SN1 reaction involves heterolysis to form the carbocation as an intermediate.

A. True
B. False
Answer» B. False
Discussion
29.

The reactivity order of alkyl halides in SN2 is

A. CH<sub>3</sub> X > 1<sup>0</sup> > 2<sup>0</sup> > 3<sup>0</sup>
B. CH<sub>3</sub> X > 2<sup>0</sup> > 1<sup>0</sup> > 3<sup>0</sup>
C. CH<sub>3</sub> X > 3<sup>0</sup> > 1<sup>0</sup> > 2<sup>0</sup>
D. CH<sub>3</sub> X > 3<sup>0</sup> > 2<sup>0</sup> > 1<sup>0</sup>
Answer» B. CH<sub>3</sub> X > 2<sup>0</sup> > 1<sup>0</sup> > 3<sup>0</sup>
Discussion
30.

When the nucleophile :OR attacks the RX, the resultant product will be

A. R – OH
B. ROR
C. R:CN
D. RNHR
Answer» C. R:CN
Discussion
31.

The halide ion is an extremely

A. Weak base
B. Weak acid
C. Strong base
D. Strong acid
Answer» B. Weak acid
Discussion
32.

The functional group in alkyl halide is

A. Hydroxyl group
B. Halogen atom
C. Inert gas
D. All of the mentioned
Answer» C. Inert gas
Discussion
33.

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
Answer» D. Nucleophile
Discussion