Isomerism

Question 1

isomerism

Answer 1

phenomenon of existing 2 or more molecules with same molecular formula, but different structural formulas and diff phy and chem props

Question 2

isomers

Answer 2

molecules that have same molecular formula but differ in properties and arrangement of atoms in the molecule

Question 3

structural isomerism

Answer 3

arises from difference in arrangement atoms within the molecule and is independent of position of atom in the space around the molecule

Question 4

classification of structural isomerism

Answer 4

chain
position
functional group
metamerism
tautomerism
ring chain

Question 5

classification of isomerism

Answer 5

structural

stereo

Question 6

chain or nuclear isomerism

Answer 6

diff arrangement of C atoms in a C chain

Question 7

position isomerism

Answer 7

diff position of atoms or groups in C chain which remains intact in isomers

Question 8

functional group

Answer 8

have different func grps and thus belong to homologous series

Question 9

metamerism

Answer 9

isomers are formed when 2 valencies of a hetero atom are satisfied by diff alkyl grps

Question 10

tautomerism

Answer 10

isomers are co existing in eqm

Question 11

ring chain isomerism

Answer 11

arises from diff in modes of linkages of C chains to get straight chain and cyclic isomers

Question 12

geometrical isomers

Answer 12

possess the same structural formula but differ in their spatial arrangement of atoms or groups around double bond

Question 13

stereo isomerism

Answer 13

same structural formula but differ in spatial arrangement within the molecule

Question 14

2 types of configurational isomerism

Answer 14

geometrical

optical

Question 15

2 types of stereo isomers

Answer 15

configurational

confirmational

Question 16

optical activity

Answer 16

phenomenon of rotating the plane polarized light

Question 17

dextro rotatory, laevo rotatory

Answer 17

dextro: rotates plane polarized light to right
laevo: to left

Question 18

chiral C atom

Answer 18

4 valencies are satisfied by diff atoms and grps

Question 19

enantiomers

Answer 19

optically active isomers form non super imposable mirror imgs

Question 20

conditions of optical isomerism

Answer 20

1) molecule shouldnt have plane of symmetry

2) should not super impose on mirror img

Question 21

characteristics of enantiomers

Answer 21

1) identical props in all respects except in interaction with plane polarized light
2) identical chem props but differ in reactivity with optical active reagents
3) diff bio props

Question 22

diastereomers

Answer 22

stereoisomers which are not mirror imgs of a compound

Question 23

racemic mixture

Answer 23

equimolecular mixture of dextro and laevo forms of an optically active substance

Question 24

resolution of racemic mixture

Answer 24

separating d and l forms from mixture

Question 25

conformational isomerism

Answer 25

isomerism arising from the diff in conformation of the isomers

Question 26

2 forms of conformation

Answer 26

staggered

eclipsed

Question 27

types of projections of conformation

Answer 27

seahorse
newman
haworth
fischer

Question 28

proximal

Answer 28

front C atom in newman projection

Question 29

distal

Answer 29

back atom in newman projection

Question 30

2 forms in which cyclohexane can exist

Answer 30

boat form

chair form

Question 31

why do substituents larger than H generally suffer greater steric crowding when they are oriented axial rather than equatorial

Answer 31

axial bonds are parallel to each other

Question 32

2 principles of conformation in cyclohexane

Answer 32

1) chair conformations are generally more stable
2) substituents on chair conformers prefer to occupy equatorial positions due to increased steric hinderance of axial locations

Question 33

conformation

Answer 33

shape that a molecule can adopt due to the rotation around one or more single bonds

Question 34

angle strain

Answer 34

strain due to deviation from one or more ideal bond angles

Question 35

torsional strain

Answer 35

strain caused by van der Waals repulsion which can be reduced or eliminated by rotation around a single bond