Free Radical

Q.

Homolytic fission of C - C bond in ethane gives an intermediate in which carbon is?

1. sp hybridised

2. hybridised

3. hybridised

4. hybridised

Q. A tertiary butyl free radical is more stable than a secondary butyl free radical because of which of the following?

1. $+R\text{effect of}–C{H}_3\text{groups}$
2. $-R\text{effect of}–C{H}_3\text{groups}$
3. $\text{Hyperconjugation}$
4. $-I\text{effect of}–C{H}_3\text{groups}$

Q. In a carbon free radical, total number of electrons that are present around C atom are?

1. 5
2. 6
3. 7
4. 8

Q.

Boron halides are monomeric while AlCl₃ forms dimer. Why?

Q. As Carbene has 1 lone pair, can we denote it by giving CH2 a negative charge? If so what will be the difference between Carbene and Carbanion?

Q. Which of the following active intermediate has unpaired electron?

1. Carbocation
2. Carbanion
3. Free radical
4. All of these

Q. The homolytic breaking of the $C^a-C^b$ bond is easiest in:

1. 
2. 
3. 
4. 

Q.

How can a carbo action have 6 valence electrons

Q. Which of the following compound has the highest $\stackrel{\ast }{C}-H$ bond energy?

1. 
2. 
3. 
4. 

Q.

Which of the following is TRUE for carbon free radical?

1. These are add electron species

2. There are seven electrons in valence shell

3. It is paramagnetic in nature

4. Free radical generally reacts with free radicals

Q. Which of the following is not true regarding free radical intermediates?

1. They are $s{p}^2$ hybridised
2. They are electron rich species
3. All of the above
4. They are formed by the homolytic cleavage of a bond

Q.

Which of the following is a free radical?

1. $C{H}_3-\stackrel{\oplus }{C}{H}_2$

2. $C{H}_3-\stackrel{\ominus }{C}{H}_2$

3. $C_6{H}_5-\stackrel{\bullet }{C}{H}_2$

4. None of these

Q.

Which of the following is a free radical?

1. $C{H}_3-\stackrel{\oplus }{C}{H}_2$

2. $C{H}_3-\stackrel{\ominus }{C}{H}_2$

3. $C_6{H}_5-\stackrel{\bullet }{C}{H}_2$

4. None of these

Q. Why butane has only 2 isomers n butane or isobutane what will happen if we tie one carbon atom to first carbon atom then it will have 3 isomers

Q. Which of the following active intermediate has unpaired electron?

1. Carbocation
2. Carbanion
3. Free radical
4. All of these

Q.

Conversion of $C{H}_4$ to $C{H}_{3}Cl$ is an example of which of the following reaction?

1. Electrophilic substitution

2. Free radical addition

3. Free radical addition

4. Free radical substituion

Q. In a singlet carbene:

1. Two unshared electrons are present in same orbital.
2. Hybridisation of $C$ is $s{p}^3$.
3. Hybridisation of $C$ is $sp$.
4. One unpaired electron is present in p-orbital.

Q.

What is hetero atom ? What is hetero atom present in chloro methane and ethanoic acid?

Q. The homolytic breaking of the $C^a-C^b$ bond is easiest in:

1. 
2. 
3. 
4. 

Q. Assertion :A free radical is paramagnetic species. Reason: A free radical is formed in homolytic fission of covalent bond.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q. Which of the following is not true regarding free radical intermediates?

1. They are $s{p}^2$ hybridised
2. They are formed by the homolytic cleavage of a bond
3. They are electron rich species
4. All of the above

Q. Select isoelectronic species out of the following.
$CO,\to CH,\to \ddot{N}=C{H}_2,=\underset{..}{\ddot{O}},\to {\ddot{O}}^{\oplus },=\ddot{N}H>\ddot{N}H$

1. $\to CH\to N:\to {\ddot{O}}^{\oplus }$
2. $=C{H}_2,=\ddot{N}H,=\underset{..}{\ddot{O}}$
3. Both (a) and (b)
4. None of these

Q. The homolytic breaking of the $C_a–C_b$ bond is easiest in

1. 
2. 
3. 
4. 

Q.

Can : CH₃ CH(C₂H₅) CH(C₂H₅) CH₃

Be written as : CH₃ (CH(C₂H₅))₂ CH₃

Q. Which of the following orders regarding relative stability of free radicals is correct?

1. 
   $$3^o<2^o<1^o$$
2. 
   $$3^o>2^o>1^o$$
3. 
   $$1^o<2^o>3^o$$
4. $$3^o>2^o<1^o$$

Q.

In Q) 10.12 - ( i )

why does electron density near the C-Cl bond decreases with increase in electronegativity?

{ in chlorobenzene }

Q.

A free radical is :

1. Neutral in nature

2. Paramagnetic

3. All of these

4. Shortly lived species

Q.

Which of the following is a free radical?

1. $C{H}_3-\stackrel{\oplus }{C}{H}_2$

2. $C{H}_3-\stackrel{\ominus }{C}{H}_2$

3. $C_6{H}_5-\stackrel{\bullet }{C}{H}_2$

4. None of these

Q.

The reaction intermediate produced by homolytic cleavage of a bond is called:

1. Carbocations

2. Carbanions

3. Free radicals

4. Carbenes

Q.

The reaction intermediate produced by homolytic cleavage of a bond is called:

1. Carbocations

2. Carbanions

3. Free radicals

4. Carbenes