Test: Reaction Mechanism


10 Questions MCQ Test Chemistry Class 11 | Test: Reaction Mechanism


Description
This mock test of Test: Reaction Mechanism for Class 11 helps you for every Class 11 entrance exam. This contains 10 Multiple Choice Questions for Class 11 Test: Reaction Mechanism (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Reaction Mechanism quiz give you a good mix of easy questions and tough questions. Class 11 students definitely take this Test: Reaction Mechanism exercise for a better result in the exam. You can find other Test: Reaction Mechanism extra questions, long questions & short questions for Class 11 on EduRev as well by searching above.
QUESTION: 1

 In a free radical reaction, free radicals are formed at

Solution:


Here, we can see that in the initiation and termination step, radical is formed.

QUESTION: 2

 The observed order of the stability of the cabocation is:

Solution:

Alkyl groups directly attached to the +vely charged carbon stabilize the carbocations due to inductive and hyperconjugation effects.
Inductive effect:
→ Stability of carbocation 
→ More number of +I group more stable carbocation.

Hyperconjugation:

Stability 
∝Number of canonical structures
              ∝Number of H (alpha hydrogen)

QUESTION: 3

 Heterolytic cleavage is a way to cleave the:

Solution:

Heterolytic fission, also known as heterolysis, is a type of bond fission in which a covalent bond between two chemical species is broken in an unequal manner, resulting in the bond pair of electrons being retained by one of the chemical species (while the other species does not retain any of the electrons from the bond pair). When a neutrally charged molecule undergoes heterolytic fission, one of the products will have a positive charge whereas the other product will have a negative charge.

QUESTION: 4

A sequential account of each step, describing details of electron movement, energetics during bond cleavage and bond formation, and the rates of transformation of reactants into products (kinetics) is referred to as:

Solution:

The correct answer is option A
Reaction mechanism: A sequential account of each step, describing details of electron movement, energetics during bond cleavage and bond formation, and the rates of transformation of reactants into products (kinetics) is referred to as reaction mechanism.
 

QUESTION: 5

 Which of the following ions is most stable?   

Solution:

The three CH3 radicals attached to the positively charged carbon are electron repelling group. Therefore, these CH3 radicals exhibit +I effect (Inductive effect) and repel electrons towards the positively charged Carbon. This decreases the positive charge and makes the compound more stable.

QUESTION: 6

 Which among the following is a very unstable and reactive species:

Solution:

Carbocation is most reactive as it lacks electrons. So it need an electron to attain stability.

QUESTION: 7

Which of the following free radical is the most stable :

Solution:

The correct answer is option B
Electron poor species are stabilized by neighboring atoms that can donate electron density. The most common way to interpret rich neighbors here is the observation that increasing the number of alkyl groups on the carbon bearing the free radical increases its stability. 
Radical stability increases in the order methyl < primary < secondary < tertiary.
 

QUESTION: 8

A carbon species carrying a negative charge on carbon atom is known as:

Solution:

A carbanion has a negatively charged, trivalent carbon atom that has eight electrons in its valence shell. Thus, a carbanion is not electron deficient. As a result, carbanions have pyramidal geometry. Carbocations, radicals, and carbanions can be stabilized by resonance.

QUESTION: 9

A species having a carbon atom possessing a sextet of electrons and a positive charge is called as:

Solution:

Carbon atoms with its sextet are called carbocation. It is an electron deficient species.

QUESTION: 10

The organic reaction which proceeds through heterolytic bond cleavage are known as:

Solution:

In heterolytic bond cleavage the bond breaks unevenly and the shared pair of electrons is accommodated by one of the products, which produces one or more ions.As heterolytic bond cleavage gives ions. So the reaction which proceeds through heterolytic bond cleavage is an ionic reaction.

Hence B is the correct answer.

Related tests