Isomerisms

Question 1

Define Structural isomers

Answer 1

Molecules with same molecules formula, yet different structural formulas

Question 2

Define Stereoisomers

Answer 2

Molecules with Same structural & molecular formula, yet different arrangement of its atoms or bonds in space

Question 3

Name all Structural isomerism types

Describe the differences

Answer 3

Chain, Position and Functional group

Chain = same functional group but different arrangement of the carbon skeleton

Position = Same carbon skeleton & same functional group of atoms, yet these groups are attached different carbons

Functional Group = identical atoms but arranged into different functional groups

Question 4

Name all Stereoisomerisms

Describe the Differences

Answer 4

Geometric Isomers & Optical Isomers

Geometric Isomers - Occurs around a double bond, no free rotation around it causes the same atoms to be arranged differently in space

Optical isomers -Occurs when 4 different substituents are attached to one carbon atom and are arranged differently in space. Forming a molecule that is non-superimposinle

Question 5

Explain how an aldehyde and KCN react to produce a racemic mixture

Answer 5

Nitrile can attack the planar carbonyl group above or below the delta positive carbon with equal opportunity

Equal amounts of 2 enantiomers are produced that are non-superimposable , producing a racemic mixture

Question 6

Explain how geometric isomerisms form

Answer 6

There is no free rotation around a C=C , due to overlapping pi clouds of electron density above and below the planar bond.

Each carbon within the double bond has 2 different groups attached