Optical isomerism

Question 1

What are isomers?

Answer 1

• compounds with same molecular formula but have a differnet molecular structures or a different arrangement of atoms in space

Question 2

WHat do structural isomers have?

Answer 2

• different functional groups
• have functional groups attached to the main chain at different points
• have a different arrangemtn of carbon atoms in the skeleton of the molecule

Question 3

What is stereoisomerism and what are the two types?

Answer 3

• two or more compounds have the same structural formula
• different in the arrangement of the bonds in space
• two types
  
  • E-Z isomerism
  • optical isomerism

Question 4

When does optical isomerism occur?

Answer 4

• four different substituents attached to one carbon atoms
• results in two isomers that are non-superimposable mirror images of one another, but not identical

Question 5

Why are they called optical isomers?

Answer 5

• the way they differ in the way they rotate the plane of polarisation of polarised light
• either clockwise ((+)-isomer) or anticlockwise ((-)-isomer)

Question 6

What is chirality

Answer 6

• optiical isomers are said to be chiral
• the carbon bonded to the four different group is called the chiral centre
  
  • aka the asymemetric carbon atom
  • indicated by *

Question 7

WHat are the two optical isomers said to be ?

Answer 7

• a pair of enantiomers

Question 8

Are amino acids chiral?

Answer 8

• all them are except glycine

Question 9

What is lactic acid?

Answer 9

• 2-hydroxypropanoic acid
• its also chiral