Chapter 13 - Alkenes

Question 1

What are alkenes?

Answer 1

Unsaturated hydrocarbons that contain at least on C=C bond made up of a Pi and sigma bond

Question 2

How is a Pi bond formed?

Answer 2

Electrons in the adjacent P orbitals overlap above and below the carbon atoms.
Only made after sigma bonds are formed

Question 3

What bond restricts the rotation of carbon atoms?

Answer 3

Pi bnd

Question 4

What is the angle of a double bond?

Answer 4

120

Question 5

What is the shape of a double bond?

Answer 5

Trigonal Planar

Question 6

Why are alkenes more reactive than alkane?

Answer 6

High electron density of double
Pi bond is slightly easier to break.

Question 7

What intermolecular forces of attraction do alkenes have?

Answer 7

London forces due to non-polar bonds

Question 8

Are alkenes soluble in water?

Answer 8

No, non polar bonds

Question 9

What is an electrophile?

Answer 9

Species that are electrons pair acceptors

Question 10

Major products are formed from which kind of carbocation

Answer 10

• Tertiary
• Or most stable available

Question 11

In a hydration reaction what conditions are needed for electrophilic addition of H20 to an alkene?

Answer 11

• Steam (H20 (g))
• Acid catalyst

Question 12

What is the product of hydration reaction?

Answer 12

Alcohol

Question 13

What is the reaction called when a halogen is added to an alkene?

Answer 13

Halogenation

Question 14

What are the conditions needed in halogenation?

Answer 14

• H2
  Nickel catalyst

Question 15

What is hydrogenation?

Answer 15

Alkene to Alkane

Question 16

What is Markownikoffs Rule?

Answer 16

Hydrogen in hydrogen bromide will attach itself to the carbon with
more H atoms attached and less C atoms attached.

Question 17

What is an addition polymer?

Answer 17

Many polymers bonded together via rearrangement of bonds without loss of any atom/molecule

Question 18

What are monomer?

Answer 18

Molecules which combine to form a polymer

Question 19

How can plastics be disposed? (x6)

Answer 19

• Landfill
• Combustion
• Electricity generation
• Reuse
• Recycle
• Organic feedstock

Question 20

What are disadvantages of recycling?

Answer 20

• Plastics must be sorted into different types
• Expensive
• Labour intensive
• Requires high technology

Question 21

How does photodegradable polymers break down?

Answer 21

• Broken down chemically using energy with wavelengths similar to light
• Once break down begins process cannot be stopped

Question 22

What happens in organic feedstock?

Answer 22

Plastics are seperated and broken down into small organic molecules through series of reactions
- Used to produce plastics in other industries

Question 23

Disadvantage of photodegradable polymers

Answer 23

May not be exposed to sufficient light