Test: Alkynes Reaction


24 Questions MCQ Test Chemistry Class 11 | Test: Alkynes Reaction


Description
This mock test of Test: Alkynes Reaction for JEE helps you for every JEE entrance exam. This contains 24 Multiple Choice Questions for JEE Test: Alkynes Reaction (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Alkynes Reaction quiz give you a good mix of easy questions and tough questions. JEE students definitely take this Test: Alkynes Reaction exercise for a better result in the exam. You can find other Test: Alkynes Reaction extra questions, long questions & short questions for JEE on EduRev as well by searching above.
QUESTION: 1

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. Which of the following reaction would not give atleast one aldehyde product?

Solution:

Correct answer is c because when we oxidise 1 pentyne with KMnO4 in basic medium, we will get a salt of a carboxylic acid.

QUESTION: 2

Which set of reagent(s) in correct order would accomplish the following transformation?

Solution:
QUESTION: 3

The major product of the following reaction is

Solution:
QUESTION: 4

What is the final major product of the following reaction?

Solution:
QUESTION: 5

Predict major product of the following reaction.

Solution:
QUESTION: 6

What is true about the final major product of the reaction?

Solution:
QUESTION: 7

A chiral hydrocarbon has molar mass 82 and it gives effervescence when heated with Na metal. What is true about the original hydrocarbon?

Solution:

A chiral hydrocarbon -Na → H
There is terminal triple bond in the reactant hydrocarbon because,
R - C ≡ C - H -NaR - C ≡ O Na++H2
Molecular mass = 82i.e., It is C6H10
 
(a) CH3 - CH2 - CH - C ≡ CH
                     |
                   CH3
                                       H2 | Pd | CaCO3    
          CH3 - CH2 - *CH - CH = CH2
                                  |
                                CH3
       Option A is wrong as it is chiral
 
 
CH3 - CH2 - CH - C ≡ CH
                     |
                   CH3
                                   Na| NH3    
         
            CH3 - CH2 - *CH - CH = CH2
                                  |
                                 CH3
          Option B is wrong as it is chiral
CH3 - CH2 - CH - C ≡ CH
                     |
                   CH3
                                        H2 | Ni   
          CH3 - CH2 - CH - CH2 = CH2
                                 |
                                CH3
       Option C is correct as it is achiral

QUESTION: 8

A hydrocarbon X (C14H22)o n treatm ent with H2/Pt gives C14H26. Also X on treatm ent with alkaline KMnO4 followed by hydrolysis of products yields C7H12O2 which on further heating with soda lime gives cyclohexane. Hence, X is

Solution:

The correct answers are option B.
As only 4 hydrogen atoms are increased after hydrogenation, there should be only 1 3× bond. So option B is correct.
 

*Multiple options can be correct
QUESTION: 9

Direction (Q. Nos. 9 - 12) This section contains 4 multiple choice questions. Each question has fo ur choices (a), (b), (c) and (d), out of which ONE or MORE THAN ONE are correct.

Q. What is/are true about ozonolysis of 1-hexyne followed by aqueous work-up?

Solution:

The correct answers are Options A, B and C.

*Multiple options can be correct
QUESTION: 10

Which reagent(s) below results in a visible change withl-butyne and can be used to differentiate it from 2-butyne?

Solution:

The correct answer is option  A,B.
(a)  Tollen's reagent produces a white precipitate of acetylide with terminal alkyne.
(b) Fehling solution produces a red precipitate with terminal alkyne.
So $$1-butyne$$ is terminal alkyne.

*Multiple options can be correct
QUESTION: 11

Which of the following sets of reagent when applied sequentially, on 2-butyne will produce a meso product?

Solution:
*Multiple options can be correct
QUESTION: 12

The correct statement(s) regarding relative reactivity of an alkyne and an aklene is/are

Solution:

b) Alkynes suffer less steric hindrance during adsorption on the surface of metal catalyst.
Hence, alkynes are more reactive than alkene towards catalytic hydrogenation.
c) Oxidation of alkenes with the help of ozone can give alcohols, aldehydes, ketones, or carboxylic acids.
Alkynes undergo ozonolysis to give acid anhydrides or diketones. If water is present in the reaction, the acid anhydride undergoes hydrolysis to yield two carboxylic acids.
d) The triple bonds of alkynes, because of its high electron density, are easily attacked by electrophiles, but less reactive than alkenes due to the compact C-C electron cloud.
 

QUESTION: 13

Direction (Q. Nos. 13 - 14) Choices for the correct combination of elements from Column I and Column II are given as options (a), (b), (c) and (d), out of which one is correct.

Q. Column I has some alkynes and Column II has their corresponding reaction products. Match them appropriately.

Solution:
QUESTION: 14

Column I has some reactions and Column II has the characteristics of reactions and products of Column I. Match them appropriately.

Solution:
QUESTION: 15

Direction (Q. Nos. 15 - 20) This section contains 2 paragraphs, each describing theory, experiments, data, etc. Six questions related to the paragraphs have been given. Each question has only one correct answer among the four given options (a), (b), (c) and (d).

Passage I

Unlike alkenes, alkynes undergo nucleophilic addition as well as electrophilic addition as :

 

Q. Which of the following best describes what happens in the first step in the mechanism of reaction shown below?

Solution:
QUESTION: 16

Passage I

Unlike alkenes, alkynes undergo nucleophilic addition as well as electrophilic addition as :

 

Q. Rates of Br2 addition were measured for a series of alkynes, giving the data shown.

Assuming that Br2 addition to alkynes proceeds through rate determining formation of cyclic bromonium ion, what generalisations can you make about the structure of rate determining transition state?

Solution:
QUESTION: 17

Passage I

Unlike alkenes, alkynes undergo nucleophilic addition as well as electrophilic addition as :

 

Q. Nucleophilic addition can occur on alkynes that bear strong electron withdrawing group such as — CF3 on the triple bond. Predict product of the following reaction :

Solution:
QUESTION: 18

Passage II

Two isomeric alkynes A and B have molecular formula C8H14 A on treatment with ammoniacal AgNO3 solution forms a white precipitate while B on similar treatment formed no precipitate. Also both A and B are chiral and hydrogenation of either A or B with H2/Pt gives the same achiral hydrocarbon C(C8H18). Treatment of A with HgSO4 /H2SO4 (aq) gives D(C8H16O) a s major product while sim ilar treatment of B, mixture of D and E in comparable amounts are formed.

 

Q. The structures of A and B are respectively

Solution:
QUESTION: 19

Passage II

Two isomeric alkynes A and B have molecular formula C8H14 A on treatment with ammoniacal AgNO3 solution forms a white precipitate while B on similar treatment formed no precipitate. Also both A and B are chiral and hydrogenation of either A or B with H2/Pt gives the same achiral hydrocarbon C(C8H18). Treatment of A with HgSO4 /H2SO4 (aq) gives D(C8H16O) a s major product while sim ilar treatment of B, mixture of D and E in comparable amounts are formed.

 

Q. The correct statement regarding A and B is

Solution:
*Multiple options can be correct
QUESTION: 20

Passage II

Two isomeric alkynes A and B have molecular formula C8H14 A on treatment with ammoniacal AgNO3 solution forms a white precipitate while B on similar treatment formed no precipitate. Also both A and B are chiral and hydrogenation of either A or B with H2/Pt gives the same achiral hydrocarbon C(C8H18). Treatment of A with HgSO4 /H2SO4 (aq) gives D(C8H16O) a s major product while sim ilar treatment of B, mixture of D and E in comparable amounts are formed.

 

Q. What is true regarding A and B?

Solution:
*Answer can only contain numeric values
QUESTION: 21

Direction (Q. Nos. 21 - 24) This section contains 4 questions. When worked out will result in an integer from 0 to 9 (both inclusive).

Q. How many different isomeric alkynes on catalytic hydrogenation can give 2, 3, 4 -trimethyl heptane?


Solution:
*Answer can only contain numeric values
QUESTION: 22

 is treated will 2 moles of Br2, how many different isomers of products would be obtained?


Solution:
*Answer can only contain numeric values
QUESTION: 23

In the reaction below :

Q. How many different isomers of tetrabromides are formed?


Solution:

It has 2 chiral carbons which can result in 4 stereoisomers, but 1 is a meso compound. So, 3 stereoisomeric tetrabromides are formed.

*Answer can only contain numeric values
QUESTION: 24

How many reagents from the list below would give effervescence when reacted with 1-pentyne?


NaOH(l),   CH3CH2ONa(ll),
CH3CH2MgBr(lll),  NaH(IV),
NaNH2(V),   Na(VI)
NaHCO3(VII),   [(CH3)2CH]2NLi(VIII),
CH3CH2 Li(IX),   C6H5Li(X).


Solution:

Related tests