Alkenes and Polymers

Question 1

Why is a carbon double bond weaker than two carbon single bonds?

Answer 1

A carbon double bond is made of a pi bond and a sigma bond while single carbon bonds are made from sigma bonds only

Question 2

Which is stronger, a pi bond or a sigma bond?

Answer 2

Sigma bond

Question 3

Why is a pi bond weaker than a sigma bond?

Answer 3

The pi bond is further away from the nucleus so less energy is needed to break the bond

Question 4

What is a stereoisomer?

Answer 4

Compounds with the same structural formula but with a different arrangement of atoms in space

Question 5

How does structural isomerism occur?

Answer 5

• Whether the structure is branched
• The functional group can be located in different places on the carbon chain
• The functional groups may be different (e.g. ketones and aldehydes)

Question 6

What is E/Z isomerism?

Answer 6

A type of isomerism in which different groups attached to each carbon of a C=C double bond may be arranged differently in space because of restricted rotation

Question 7

Criteria for E/Z isomerism to occur

Answer 7

C=C bond must be present

Each crabon in the double bond must be attached to two different groups

Question 8

What is cis/trans isomerism?

Answer 8

A special type of E/Z isomerism in which there is a non-hydrogen group and a hydrogen group