6. Organic molecules (ISOMERISM)

Question 1

Define what is meant by a structural isomer

Answer 1

Molecules which have the same molecular formula but differ in the way there atoms are arranged (their structural formula)

Question 2

What are the 2 types of isomers

Answer 2

Structural isomers
Sterioisomers

Question 3

What are the the 3 types of structural isomers

Answer 3

Chain isomers
Positional isomers
Functional group isomers

Question 4

Describe what is meant by a chain isomer

Answer 4

Molecules that have the same molecular formula but different skeletal formula
eg: 2-methylhexane and 3,3dimethylpentane are both chain isomers of C7H16

Question 5

Describe what is meant by a positional isomer

Answer 5

Compounds with same molecular formula but different position of functional group
eg: Butan-1-ol and Butan-2-ol

Question 6

Describe what is meant by a functional group isomer

Answer 6

Molecules with same molecular formula but with but different functional groups

Question 7

Define stereoisomers

Answer 7

Compounds that have the same structural formula have different arrangements of atoms in space (displayed formula)

Question 8

Give the 2 types of stereoisomer

Answer 8

Geometrical isomers
Optical isomers

Question 9

When do we use E and Z isomers instead of cis and trans

Answer 9

Use E and Z when there is 2 different groups attached to C=C
Cis and trans used when there is 1 same group and 1 different group on C=C

Question 10

When is an E isomer used compared to a Z isomer

Answer 10

E is when the highest atomic number chains are on different sides of the C=C bond. Z is when they are on ze zame zide
–> uses priority. Figure out prority group first on the left hand side of double bond, then the right hand side, and see if they are on the same or different sides.