CPU 5 - Esters (Carboxylic Acids And Acid Derivatives)


25 Questions MCQ Test | CPU 5 - Esters (Carboxylic Acids And Acid Derivatives)


Description
This mock test of CPU 5 - Esters (Carboxylic Acids And Acid Derivatives) for Class 12 helps you for every Class 12 entrance exam. This contains 25 Multiple Choice Questions for Class 12 CPU 5 - Esters (Carboxylic Acids And Acid Derivatives) (mcq) to study with solutions a complete question bank. The solved questions answers in this CPU 5 - Esters (Carboxylic Acids And Acid Derivatives) quiz give you a good mix of easy questions and tough questions. Class 12 students definitely take this CPU 5 - Esters (Carboxylic Acids And Acid Derivatives) exercise for a better result in the exam. You can find other CPU 5 - Esters (Carboxylic Acids And Acid Derivatives) 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 is correct.

Q. 

(+) -2-butanol is first treated with tosyl chloride then with C6H5ONa There was obtained secondary butyl benzoate. This ester when subjected to alkaline hydrolysis, alcohol and acid are recovered back. What is true about stereochemistry of 2-butanol obtained after hydrolysis?

Solution:


In ester hydrolysis, alkyl-oxygen bond is not cleaved, hence retention of configuration .

QUESTION: 2

Predict the major addition product of the following reaction

Solution:

QUESTION: 3

What is the major organic product of the following reaction?

Solution:


QUESTION: 4

Choose the best method that could perform the following transformation.

Solution:



QUESTION: 5

Arrange the following esters in the increasing order of reactivity in base catalysed hydrolysis reaction.




Solution:

Electron withdrawing group increases electrophilic character of ester, hence reactivity in hydrolysis reaction. (IV) is most reactive as it has the best leaving group.

QUESTION: 6

Which ester given below can most easily be produced by acid catalysed esterification (Fischer’s esterification)?

Solution:

Ester which contain primary alcohol fraction can most easily be synthesised by Fischer's synthesis. Secondary and tertiary alcohols have chances of acid catalysed dehydration.

QUESTION: 7

Which of the following ester is most likely to undergo unimolecular acid catalysed hydrolysis reaction?

Solution:

Esters that produces a highly stable carb oca tion by alkyl-oxygen cleavage in present case) are more likely to undergo unimolecular acid catalysed hydrolysis.

QUESTION: 8

Which reaction and indicated product with specified stereochem istry is most accurate?

Solution:

In this case, high concentration of NaOH forces hydrolysis to proceed by bimolecular mechanism otherwise it may proceed by unimolecular carbocation mechanism. In BAC2, configuration at a-carbon of alcohol remains unchanged.

*Multiple options can be correct
QUESTION: 9

One or More than One Options Correct Type

Direction (Q. Nos. 9-14) This section contains 6 multiple choice questions. Each question has four choices (a), (b), (c) and (d), out of which ONE or MORE THAN ONE are correct.

Q. 

What is/are true regarding the following Fischer’s ester synthesis?

Solution:

In Fischer esterification, sp2 oxygen of acid is first proto nate d which will undergo nucleophilic attack by ROH in the second, slow, rate determining step.

*Multiple options can be correct
QUESTION: 10

Consider the following acid catalysed esterification reaction,

Q. 

The correct statement concerning the above reaction is/are

Solution:

If cyclic ester containing five or six membered ring is formed, it is favoured over intermolecular condensation. Also :

*Multiple options can be correct
QUESTION: 11

In which of the following hydrolysis reaction of esters, reactant and products are correctly matcheed ?

Solution:





*Multiple options can be correct
QUESTION: 12

In which of the following reaction(s), reactant and products are correctly matched?

Solution:






*Multiple options can be correct
QUESTION: 13

If  is treated with  in the presence of H2SO4, possible esters formed is/are

Solution:


Therefore, in ester O18 of acid may or may not be present but O18 of  would always be there.

*Multiple options can be correct
QUESTION: 14

The correct statement regarding the following transformation is/are

Solution:

(a) Excess of ethanol drive the equilibrium in forward direction (Le-Chatelier's principle).
(b) Transesterification proceed well in both acidic and basic medium.
(c) It is wrong, condition can be made suitable so that even larger alcohol can replace the smaller one.
(d) In the presence of acid or base catalyst, reaction is always bimolecular second order.

QUESTION: 15

Comprehension Type

Direction (Q. Nos. 15-17) 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

Treatment of 2,4-pentanedione with excess of KCN(aq)and acetic acid followed by hydrolysis in the presence of H2SO4 gives two products A and B, both having molecular formula C7H12O6. When heated, B first gives a lactonic acid C7N10O5 and finally a dilactone P (C7H8O4).

Q. 

What is the correct structure of A?

Solution:






Second step of lactonisation is possible with B.

QUESTION: 16

Treatment of 2,4-pentanedione with excess of KCN(aq)and acetic acid followed by hydrolysis in the presence of H2SO4 gives two products A and B, both having molecular formula C7H12O6. When heated, B first gives a lactonic acid C7N10O5 and finally a dilactone P (C7H8O4).

Q. 

What is the correct structure of P?

Solution:



Discussed in the previous question.

QUESTION: 17

Treatment of 2,4-pentanedione with excess of KCN(aq)and acetic acid followed by hydrolysis in the presence of H2SO4 gives two products A and B, both having molecular formula C7H12O6. When heated, B first gives a lactonic acid C7N10O5 and finally a dilactone P (C7H8O4).

Q. 

A also lactonises on heating. What is the correct structure of lactone obtained from A?

Solution:




Product shown in question-20. The —COOH and —OH are on anti sides, do not lactonise further.

QUESTION: 18

Statement Type

Direction (Q. Nos. 18-21) This section is based on Statement I and Statement II. Select the correct answer from the codes given below.

Q. 

Statement I : Ester formation from acid and alcohol occur in acidic medium but not in alkaline medium. However, hydrolysis of esters proceeds in both acidic and alkaline medium.

Statement II : In alkaline medium carboxylic acid is neutralised into salt which do not undergo nucleophilic attack by alcohols.

Solution:

RCOOH is neutralised to RCOONa which itself is a nucleophile and it does not undergo nucleophilic attack by poor nucleophile ROH.

QUESTION: 19

Statement I : When ethyl propanoate is refluxed with butanol in slightly acidic condition at the boiling point of ethanol, butylpropanoate is formed.

Statement II : During trans esterification, larger alcohols always displaces the smaller one.

Solution:

Ethanol has lower boiling point than butanol, evaporates immediately after it is formed which enables the above reaction to proceed in forward direction.
However, suitable condition can be made to reverse the above reaction.

QUESTION: 20

Statement I : If CH3COOCH(CH3)C6H5 is heated with dilute NaOH solution, racemic mixture of 1-phenyl ethanol is formed.

Statement II : At low hydroxide concentration and alcohol part of ester being capable of forming stable carbocation, hydrolysis proceeds preferably by unimolecular alkyl oxygen cleavage mechanism.

Solution:

At low hydroxide condition this hydrolysis proceeds as

The planar carbocation then undergo nucleophilic attack by OH- giving racemic mixture.

QUESTION: 21

Statement I : p-nitrobenzoic acid is more reactive than benzoic acid in acid catalysed esterification reaction.

Statement II : Rate determining step in Fischer’s esterification reaction of carboxylic acid in nucleophilic attack alcohols on protonated acid.

Solution:

Electron withdrawing nitro group increases electrophilic character of —COOH, hence increases reactivity in Fischer’s esterification.

*Answer can only contain numeric values
QUESTION: 22

One Integer Value Correct Type

Direction (Q. Nos. 22-25) This section contains 4 questions. When worked out will result in an integer from 0 to 9 (both inclusive).

Q. 

If a mixture containing ethyl acetate and ethyl propanoate is heated in the presence of C2H5ONa, how many different condensation products would be formed?


Solution:




*Answer can only contain numeric values
QUESTION: 23

In the following lists of reactions, how many of them gives ester as the major organic product?







Solution:

Reactions (I), (III), (IV), (V), (VI), (VIII) and (IX) give ester.

*Answer can only contain numeric values
QUESTION: 24

How many different isomers exist for C3H6O2 which reduces Tollen’s reagent as well as forms C5H8O3 upon treatment with acetic anhydride ?


Solution:


α-hydroxy ketones also reduces Tollen's reagent.

*Answer can only contain numeric values
QUESTION: 25

A hydroxy acid has molecular formula C5H10O3 and it iactonises (forms cyclic esters) on heating. If only five and six membered lactones are considered, how many different isomers of lactones are possible?


Solution: