Reactions of alkenes

Question 1

Why are alkenes more reactive than alkanes?

Answer 1

• Unsaturated hydrocarbons (contains ateleast 1 carbon-carbon double bond)
• Their double bond can open up to bond to atoms of other molecules (addition reactions)
• This allows us to add molecules onto other alkenes

Question 2

Alkene + hydrogen

Answer 2

• Hydrogenation
• Using catalyst
• Alkene + hydrogen = alkane

Question 3

Alkene + water

Answer 3

• Hydration
• Using catalyst and high temperatures
• Alkene + water = alcohol

Question 4

Alkene + halogen

Answer 4

• Halogenation
• Happens at room temperature
• Alkene + halogen = halogenation
• E.G: ethene + bromine = dibromoethane

Question 5

What must be done when reacting an alkene with water?

Answer 5

• We must seperate the alcohol form the water and unreacted alkene
• Done using fractional distillation