GOC

Question 1

What is Resonance?

Answer 1

Delocalization of π+lone pair

Question 2

What is Mesomeric effect?

Answer 2

Effect of functional group on a molecule.

Question 3

What is +M effect?

Answer 3

occurs in presence of EDGs (having one electron pair on the atom joined to the benzene ring or π.
*-ve charges on o- and p- positions.

Question 4

What is -M effect?

Answer 4

Occurs in the presence of EWGs (the atom joined to the ring is multiply bonded to a more EN atom).
*+ve charge on o- and p- positions

Question 5

series of +M

Answer 5

-O- ≻ -NH2 ≻ -NHR ≻ -NR2≻ -OH ≻ - NHCOR ≻ -OCOR ≻ -Ph ≻ -F ≻ -Cl ≻ -Br ≻ -I ≻ -NO

Question 6

Series of -M

Answer 6

-NO2 ≻ - CN ≻ - SO3H ≻ -CHO ≻ -COR ≻ -COOCOR ≻ -COOR ≻ -COOH ≻ -CONH2 ≻ -COO-

Question 7

Resonance effect explains the

Answer 7

1. Stabilities of carbocations, free radicals and carbanions.
2. Acidic and basic strengths
3. direction influence in reactions of substituted benzenes.

Question 8

How stability depends on the resonance?

Answer 8

directly proportional to the resonating structures and |resonance energy|.

Question 9

Explain quasi-aromaticity.

Answer 9

When +ve or -ve charge is part of aromaticity it becomes more stable.

Question 10

Sequence rules for the stability of resonance structures.

Answer 10

1. a greater number of covalent bonds/π bonds.
2. complete octet of all atoms.
3. the structure with least formal charges.
4. the structure with the least separation of charges.
5. Negative charge on more EN atom and vice versa.
6. Species having equivalent resonance structures.

Question 11

What is Inductive effect?

Answer 11

The polarization of sigma bonds along the chain due to the presence of a more EN atom / group. .