Isomers

Question 1

What is an isomer?

Answer 1

2 or more molecules with the same molecular formula but different structure

Question 2

What is structural isomerism?

Answer 2

2 or more molecules with the same molecular formula but different structural formula

Question 3

What is positional isomerism?

Answer 3

2 or more molecules with the same molecular formula but different placement of the functional group

Question 4

What is functional group isomerism?

Answer 4

2 or more molecules with the same molecular formula but different functional group

Question 5

What is stereoisomerism?

Answer 5

2 or more molecules with the same structural formula but different displayed

Question 6

What is a trans stereoisomer?

Answer 6

The same element is on the same side

Cl           H
    \        /
      C=C
     /       \
H          Cl

Question 7

What is a cis stereoisomer?

Answer 7

The same element is on a different side

Cl           Cl
    \        /
      C=C
     /       \
H          H

Question 8

How to identify an E-Z stereoisomer?

Answer 8

Look at the left carbon and number the element or compound attached with the highest atomic number 1 and the lower one 2.
Do this with the right carbon.

Question 9

What is a E-stereoisomer?

Answer 9

When the 2 elements with the biggest atomic number are on opposite sides
(If both 1’s are on the same side)

Question 10

What is a Z-stereoisomer?

Answer 10

When the 2 elements with the biggest atomic number are on the same side
(If both 1’s are on the same side)

Question 11

What are the criteria for stereoisomerism?

Answer 11

• There must be a double bond to prevent rotation

- Each carbon on the double bond must have 2 different atoms or groups attached