Reactions of Alkenes

Question 1

Hydrogenation, Reagents and Conditions

Answer 1

• Hydrogen gas + gaseous alkene
• nickel catalyst
• 150 degrees

Question 2

Addition of Halogens

Answer 2

• Reacts at room temperature
• halogen adds across the double bond to give a di-substituted halogenoalkane
• reaction called halogenation
• when bromine added to a sample containing an alkene, colour changes from orange to colourless, used as a test for C=C double bond

Question 3

Addition of hydrogen halides

Answer 3

• adds across the double bond of an alkene to produce a halogenoalkane
• gases at room temperature and are bubbles into liquid alkanes

Question 4

Hydration

Answer 4

• addition of steam to alkenes one method of preparing alcohols
• steam and gaseous alkene are heated to high temperature and high pressure
• phosphoric acid catalyst
• double bond breaks and OH group is added

Question 5

Polymerisation

Answer 5

• Ziegler-Natta catalyst
• 200 degrees
• high pressure