4.1.3 Alkenes Flashcards

1
Q

are alkenes saturated or unsaturated

A

unsaturated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

general formula of an alkene

A

CnH2n

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the shape and bond angle of an alkene

A

trigonal planar, 120

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are the two distinct bonds in alkenes

A

pi bonds and sigma bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

which bonds are weaker

A

pi bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

structural isomerism

A

have the same molecular formula but a different structural formula

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

stereoisomerism

A

compounds with the same structural formula but with different arrangements of atoms in space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

E/Z isomerism

A

arises from having 2 different groups on each carbon atom of the of the carbon double bond
and the restricted rotation about the carbon double bond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

in E/Z isomerism which atoms have the highest priority

A

the highest priority is the highest atomic number

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

in E/Z isomerism if both priorities are on the same side what is the isomer

A

Z-isomer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

in E/Z isomer if the priorities are on opposite sides what is the isomer

A

E-isomer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what isomer is the same as E

A

trans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what isomer is the same at Z

A

cis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What 5 reactions can take place between alkanes

A
  1. Hydrogenation (H2)
  2. Halogenation (HX)
  3. Halogenation (X2)
  4. Hydration (H2O)
  5. Addition polymerisation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What conditions are required for the addition of hydrogen reaction

A

Hydrogen H2

Nickel catalyst

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the importance of a hydrogen addition reaction

A

Bonds become saturated

Used in the manufacturing of margarine

17
Q

What conditions are required for the addition of halogens

A

Cl2, Br2, I2

Room temp

18
Q

What is the context of the addition of halogens

A

Addition of bromine test presence of double bonds

Iodine used to test unsaturation in vegetable oils

19
Q

What is the test for alkenes

A

The decolorisation rising of bromine water

20
Q

What conditions are required for the addition of hydrogen halides

A

HCL, HBr, HI

Room temp

21
Q

What happens when unsymmetrical alkenes react with hydrogen halides and other unsymmetrical molecules

A

Two isomeric products are formed

22
Q

What are the conditions needed for addition of steam reaction

A

H2O
Temp >100c
Phosphoric acid catalyst

23
Q

What is the importance of steam addition reactions

A

Used in industrial manufacture of alcohols

24
Q

Markovnikoff’s Rule

A

When a compound HX is added to an unsymmetrical alkene, the hydrogen becomes attached to the carbon with the most hydrogens attached to it already

25
Q

Carbocation

A

A molecules in which a carbon atoms bears three bonds and a positive charge

26
Q

Major product

A

Formed from the most stable carbocation intermediate in the mechanism

27
Q

Minor product

A

Formed from the least stable carbocation intermediate in the mechanism

28
Q

polymers

A

long chained moleculesmader by the joining of many small chained molecules called monomers

29
Q

what is the problem with plastics

A

they do not breakdown naturally

30
Q

what are the benefits of processing waste polymers

A

polymers can be turned into chemicals which can be fed into manufacturing of useful products (alkenes to make new polymers, this is called feedstock)
when burned polymers produce energy which can generate electricity

31
Q

what is the environmental danger of CO

A

it is a poisonous gas

32
Q

what is a solution to the production of CO in incineration

A

supply more oxygen to ensure complete combustion to CO2

33
Q

what is the environmental danger of HCL

A

acidic so can cause acid rain which can damage buildings

34
Q

what is a solution to the production of HCL in incineration

A

removing HCL before released by reacting it with bases (NaOH) to neutralise the acid
or bubbling water through it to dissolve the HCL

35
Q

how can chemists create more sustainable degradable plastics

A

biodegradables can be developed from renewable raw materials (starch)

degradation of biodegrables in landfill is due to bacterial activity with soil or air

photodegradables decompose in the presence of sunlight

polyactic for drinks cups

food trays made from sugar cane fibre replacing polystyrene