4.1 isomerism

Question 1

structural isomerism

Answer 1

same mf but diff sf

Question 2

stereoisomerism

Answer 2

same mf and SAME sf but a diff arrangement of atoms in space

Question 3

how to identify optical isomer?

Answer 3

• look for chiral center
• atom without molecule usually carbon which has 4 diff atoms/groups attached
• place asterix

Question 4

what are two compounds that are optical isomers of each other called?

Answer 4

enantiomers

Question 5

what’s a mixture containing 50/50 of the two isomers(enantiomers) called?

Answer 5

race mate or racemic mixture - an eqimolar mixture of two enantiomers

Question 6

similarities and differences of optical isomers

Answer 6

• same chemical and physical properties
  EXCEPT effect on plane polarised light

Question 7

what can optical isomers do and what do racemates do?

Answer 7

optical- can rotate plane of polarised light (optically active). one enantiomers rotates in one direction and the other rotates by the same amount in the opposite direction
racemate- no effect on plane of polarised light(optically inactive) each enantiomer cancels out the effect of the other

Question 8

how to identify between two optical isomers?

Answer 8

• separate the two isomers
• place one in polirimiter
• measure rotation plus direction of change on plane of polarised light
• one OI ratates to left and other to the right
• both rotate by the same angle

Question 9

in drugs why is only one optical
isomer used?

Answer 9

side effects from other optical isomer

Question 10

exam q: state how the two enantiomers of this compound ben be distinguished:

Answer 10

rotate the plane of polarised light in opposite directions