Reactions of alkenes

Alkenes all react similarly as they have the same __, making them a __

• Functional group

• Homologous series

What are the 4 main types of reactions of alkenes to know?

• Combustion

• Hydrogenation

• Hydration

• Reacting with halogens

What happens during combustion of alkenes?

We produce carbon dioxide, water, and unburnt carbon particles. This is cause it’s an incomplete combustion.

Hydrogenation means…

Reacting with hydrogen

What is made when an alkene reacts with hydrogen?

An alkane

Why is an alkane produced from the reaction of an alkene and hydrogen?

Because the hydrogen atoms add across the double bond of carbon, therefore turning it into a single bond

What conditions are needed for hydrogenation of an alkene?

• Temperature of 150 degrees

• A nickel catalyst

Hydration means…

Reacting with water

What is made when an alkene reacts with water?

An alcohol

What are the conditions needed to react an alkene with water?

• 300 degrees temperature

• Pressure of 70 atmospheres

• The water must be in the form of steam

• Use phosphoric acid as a catalyst

Is the reaction of an alkene and water reversible?

Yes

Since the reaction of water and an alkene is reversible…

Any unreacted alkene or water can be passed back through the catalyst

Alkenes react __ with halogens

Rapidly

When an alkene reacts with a halogen…

The two halogen atoms are added across the carbon double bond, turning it back into a single one.