Alkenes

Question 1

What are Alkenes?

Answer 1

Alkenes are unsaturated hydrocarbons with at least one carbon to carbon double bond

Question 2

What is the general formula for alkenes

Answer 2

CnH2n

Question 3

Why are alkenes more reactive than alkanes ?

Answer 3

Alkenes are more reactive due to the exposed and available pi electrons in the double bond.

Question 4

What are Olefines

Answer 4

Olefines are the common name for alkenes since the lower members form oily products with chlorine and bromine

Question 5

What is ethylene?

Answer 5

Ethylene or ethene is a colourless flammable gas with a sweet odour that most fruits and vegetables produce to speed up ripening

Question 6

Example of ethylene usage

Answer 6

0.1 mg for 24 hours can ripen 1 kg of tomatoes

Question 7

Lycopene

Answer 7

A polyene that gives tomatoes its bright red colour

Question 8

How are alkenes classified?

Answer 8

According to the number of alkyl group substituents that are attached to the sp2 hybridised C atom of the double bond

Question 9

Monosubstituted alkenes

Answer 9

One alkyl group is attached to the sp2 hybridised carbon atom of the double bond

Question 10

Disubstituted alkenes

Answer 10

Two alkyl groups attached to the sp2 hybridised carbon atom of the double bond.
Can be cis trans or geminal

Question 11

Cis

Answer 11

Same side

Question 12

Trans

Answer 12

Opposite side

Question 13

Geminal

Answer 13

Both substituents on one carbon atom

Question 14

Trisubstituted alkene

Answer 14

Three alkyl groups are attachted to the sp2 hybridised carbon atom of the double bond

Question 15

Tetrasubstituted

Answer 15

Four alkyl groups attached to the sp2 hybridised carbon atom of the double bond

Question 16

Do alkyl groups affect the alkenes?

Answer 16

Yes they affect the stability of the double bond and the chemical reactivity