Electronic Concept In Organic Chemistry

Question 1

What is inductive effect?

Answer 1

Inductive effect is an electronic effect occuring due to polarization of sigma bonds as a result of the difference in electronegativity values between carbon and the atom bonded to it.

Question 2

What are the types of inductive effect?

Answer 2

Negative and positive inductive effects.

Question 3

What is negative inductive effect?

Answer 3

Negative inductive effect occurs when the carbon atom directly attached to the more electronegative atom pulls the electron cloud away from the other carbons linked to it in the direction of the electronegative atom.

Question 4

What is an example of negative inductive effect?

Answer 4

The effect found in 1-chloropropane.

H3C–CH2–CH2–Cl

Where the carbon atom closest to chlorine exerts a negative inductive effect.

Question 5

What is positive inductive effect!

Answer 5

This occurs when branched carbon atoms donate electrons to a central carbon atom; these donating carbons exert a positive inductive effect.

Question 6

What is an example of positive inductive effect?

Answer 6

The effect found in 2,2-dimethylpropane.
CH3
|
CH3—C—CH3
|
CH3
Here, the carbon atoms at the extremes donate their electrons to the carbon at the centre.

Question 7

What is mesomeric effect?

Answer 7

Mesomeric effect is the resulting polarity in an organic molecule due to the interactions between two pi bonds, or a pi bond and a lone electron pair on an adjacent atom.

Question 8

What is an example of mesomeric effect?

Answer 8

The effect found in 2-propanone:

H3C. H3C
\ \
C = O <==> C+ — O-
/ /
H3C H3C

Question 9

What are the differences between inductive effect and mesomeric effect?

Answer 9

1. Inductive effect only occurs in saturated organic molecules while mesomeric effect occurs in unsaturated organic molecules.
2. Inductive effect involves sigma bonded electrons while mesomeric involves pi bonded electrons.
3. Inductive effect is transmitted through a short distance in the chain while mesomeric effect can be transmitted from one end to the other.
4. Inductive effect does not involve any form of cleavage while mesomeric effect involves heterolytic bond cleavage.

Question 10

What is steric effect?

Answer 10

Steric effect is an electronic effect due to the spatial arrangement of atoms of a molecule that may affect the rates of chemical reactions.