Test: E1 Reactions & Related Reactions


16 Questions MCQ Test Chemistry Class 12 | Test: E1 Reactions & Related Reactions


Description
This mock test of Test: E1 Reactions & Related Reactions for Class 12 helps you for every Class 12 entrance exam. This contains 16 Multiple Choice Questions for Class 12 Test: E1 Reactions & Related Reactions (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: E1 Reactions & Related Reactions quiz give you a good mix of easy questions and tough questions. Class 12 students definitely take this Test: E1 Reactions & Related Reactions exercise for a better result in the exam. You can find other Test: E1 Reactions & Related Reactions extra questions, long questions & short questions for Class 12 on EduRev as well by searching above.
QUESTION: 1

Only One Option Correct Type

Direction (Q. Nos. 1-8) This section contains 8 multiple choice questions. Each question has four choices (a), (b), (c) and (d), out of which ONLY ONE option is correct.

Q. 

The incorrect statement concerning E1 reaction is

Solution:

E1 Reactions involve carbocation intermediates which has characteristics of rearrangement into more stable carbocation, hence involves more than one transition states (usually).

QUESTION: 2

The correct statement regarding a unimolecular elimination reaction is

Solution:

E1 reaction proceeds via carbocation intermediate, rearrangement of carbon skeleton is very common in this reaction.

QUESTION: 3

Consider the following reaction,

 

Q. 

The correct statement concerning I and II is

Solution:

This is an example of E1 reaction and more substituted alkene (I) is formed as the major product.

QUESTION: 4

Consider the following elimination reaction,

When reaction is carried out with C2H5ONain ethanol, 2-menthene is the major product while 3-menthene is the major product if reaction is substrate is heated in ethanol only. It is due to

Solution:

With strong base C2H5ONa, reaction proceeds by E2 mechanism. Since, there is no H in the anti position at tertiary β-carbon, deprotonation occur from secondary β-carbon giving 2-menthene as the major product. On the other hand, with weak base, reaction proceeds by E1 mechanism and the most stable tertiary carbocation formed, gives the major product 3-menthene.

QUESTION: 5

The reaction of tertiary butyl chloride in water to yield tertiary butyl alcohol is not appreciably affected by dissolved NaF; in DMSO, however, NaF bring about rapid formation of isobutene. It is because of

Solution:

Polar aprotic solvents DMSO strongly favour E2 reaction giving isobutene product.

QUESTION: 6

When (CH3)3C — Cl is heated in ethanol, both alkene and ether are formed simultaneously by E1 and SN1 reaction. Which of the following will have adverse effect on both of the above reaction?

Solution:

Both SN1 and E1 reaction involve formation of carbocation intermediate in slow rate determining step as :


Presence of NaCI derive the above reaction in backward direction by Le-Chatelier’s principle, hence has adverse effect on both E1 and SN1 reaction.

QUESTION: 7

Consider the following reaction,

 

Q. 

Increasing temperature increases the proportion of elimination (E1) product because

Solution:




Reaction (II) leads to greater increase in entropy (Δn = 1). Hence, favoured at higher temperature due to greater decrease in ΔG than for reaction (I).

QUESTION: 8

Which is the least reactive halide in both E1 and SN1 reaction?

Solution:

Carbocation at bridge head carbon of bicyclic compound is highly unstable due to lack of planarity.

*Multiple options can be correct
QUESTION: 9

Direction (Q. Nos. 9-11) This section contains 3 multiple choice questions. Each question has four choices (a), (b), (c) and (d), out of which ONE or MORE THAN ONE are correct.

Consider the following reaction,

Solution:

Reaction proceeds by E1 mechanism



*Multiple options can be correct
QUESTION: 10

Consider the following elimination reaction,

Solution:

Reaction proceeds by E1 mechanism.


*Multiple options can be correct
QUESTION: 11

The correct statement regarding an E1 reaction is/are ?

Solution:

In E1 reaction, carbocation intermediate undergo deprotonation in the fast, non-rate determ in ing step, hence C—H and C—D bo nd s react at same rate. However, C—X bond is broken in first, slow, non-rate determ in ing step, hence R— I127 reacts at faster rate than R— I131.

QUESTION: 12

Comprehension Type

Direction (Q. Nos. 12-14) This section contains a paragraph, describing theory, experiments, data, etc. Three questions related to the paragraph have been given. Each question has only one correct answer among the four given options (a), (b), (c) and (d).

Passage

Consider the following reaction. The tertiary butyl group can be cis or trans to tosylate group. Answer the following questions based on the knowledge of E2 and E1 reaction mechanism.

Q. 

The correct statement concerning above elimination reaction is

Solution:

The reaction involves E2 elimination m echanism in w hich base approaches to β-H from side anti to leaving halide in the rate determining step. Hence, if tertiary butyl group is cis to tosylate, it would not give steric hindrance to the base approaching from opposite side to β-H

QUESTION: 13

Consider the following reaction. The tertiary butyl group can be cis or trans to tosylate group. Answer the following questions based on the knowledge of E2 and E1 reaction mechanism.

Q. 

When tertiary butyl group and tosylate group are trans, the correct statement is

Solution:

When tertiary butyl group is trans to tosylate, E2 reaction will be difficult and E1 reaction would be preferred. Since, E1 reaction occur slowly and hydrogen is lost in fast step, both H and D will be lost with equal ease.

QUESTION: 14

Consider the following reaction. The tertiary butyl group can be cis or trans to tosylate group. Answer the following questions based on the knowledge of E2 and E1 reaction mechanism.

Q. 

If the rate of reaction is independent of NaOEt concentration, it is concluded that

Solution:

When tertiary butyl group is trans to leaving halide, E2 reaction will be highly sterically hindered and E1 reaction would be preferred.

*Answer can only contain numeric values
QUESTION: 15

One Integer Value Correct Type

Direction (Q. Nos. 15 and 16) This section contains 2 questions. When worked out will result in an integer from 0 to 9 (both inclusive).

Consider the following reaction,

Q. 

In principle, how many different alkenes are possible by the above elim ination reaction?


Solution:

Total 8 alkenes


*Answer can only contain numeric values
QUESTION: 16

E1 reaction alw ays com petes with SN1 reaction. How many SN1 products are formed in principle in the question number 20?


Solution:

Total seven isomers.