Organic Chemistry

Question 1

F Wohler synthesized organic compound:

Answer 1

NH4CNO –>NH2CONH2
(Ammonium–>(urea)
cyanate)

Question 2

Functional groups in decreasing order

Answer 2

(-COOH),(-SO3H),(-COOR),(COCl),(-CONH2),(-CN),(-HC=O),(>C=O),(-OH),(-NH2),(>C=C<),-(C≡C-)

Question 3

The size of the hybrid orbital decreases as

Answer 3

percentage of s-character increases

Question 4

EN of the Hybrid Orbital is

Answer 4

sp > sp2 > sp3

Question 5

Breaking of Bonds:

Answer 5

Homolytic fission & heterolytic fission

Question 6

Homolytic Fission or Homolytic Cleavage

Answer 6

Each atom separates with 1 e’ in this type of bond breaking, resulting in formation of free radicals
Two half-headed or fishhook arrows represent bond breaking. 1 e’s movement is depicted by a half-headed arrow. Radicals are odd electron species that are neutral.

Question 7

Heterolytic Fission or Homolytic Cleavage

Answer 7

Shared pair of e’s are transferred to more electronegative part. As a result, a cation and an anion are formed (ion-pair).
A full-headed arrow represents the bond breaking & depicts the movement of two e’s.
e’ movement is always represented by curved arrows, either half-headed or full-headed.

Question 8

Inductive Effect:

Answer 8

When two unlike atoms form a covalent bond, the e’ pair that forms sigma bond is shifted slightly towards more electronegative species.

Question 9

Electron Donating and Electron withdrawing Groups have ___ Inductive effect

Answer 9

+I and -I effect

Question 10

Applications of Inductive Effect

Answer 10

1. EWG raises acidic strength decreasing basic strength
2. I.E decreases as the ERG/EWG moves away

Question 11

resonance?

Answer 11

delocalization of electrons(pi electrons)

Question 12

isomerism types

Answer 12

Structural: Occurs due to different structural arrangement of atoms of a compound with same chemical formula
Stereoisomerism: Same chemical formula and bond sequence but different 3D orientation of atoms in space. It is of two types- Geometrical and Optical

Question 13

electrophiles & nucleophiles

Answer 13

Electrophiles: electron seeking
Nucleophiles: provide electron pairs or ‘nucleus seeking’

Question 14

carbocations & carbanions

Answer 14

Carbocations are carbon intermediates with a positive charge and have 6 e’s in the valence shell. It has sp² hybridization.
Carbanions are carbon intermediates with a negative charge. They have 8 e’s in the outermost shell. Their hybridization is sp³.

Question 15

free radicals

Answer 15

Carbon-free radicals are intermediates with odd e’s. They are neutral and have 7 e’s in the valence shell and have sp²

Question 16

Resonance or Mesomeric Effect:

Answer 16

When the structure of a molecule cannot be explained explicitly in a single Lewis dot structure then a number of structures are required to show the structure of the molecule. This occurs because of the delocalization of pi electrons

Question 17

Hyperconjugation Effect:

Answer 17

Ability of the sigma bond e’s of an alpha-carbon to form conjugation with adjacent pi e’s

Question 18

Electromeric Effect:

Answer 18

Shifting of e’ pairs towards more electronegative atoms in a double-bonded system in presence of a reagent.

Question 19

Methods of Purification of Organic Compounds

Answer 19

Crystallization
Sublimation
Fractional Distillation
Simple Distillation
Chromatography

Question 20

Simple Crystallization:

Answer 20

In this process, a solvent is selected for preparation of a solution in which one of the elements crystallizes out in the form of a compound.

Question 21

Sublimation:

Answer 21

Used for purifying relatively volatile organic solids

Question 22

Fractional Distillation:

Answer 22

Used for purification of two substances with less difference in boiling points

Question 23

Simple Distillation:

Answer 23

In this process, liquid is converted into vapour and vapour is transferred to another place and recovered by condensation.

Question 24

Chromatography

Answer 24

In this process, the mixture is passed through a solution or suspension where it has different rates of moving. Types are adsorption & partition

Question 25

Adsorption chromatography types:

Answer 25

column:separaton of a mixture over a column of adsorbent in a glass tube
thin layer:separation of a mixture over a thin layer of adsorbent on glass plate