Alkenes Flashcards

1
Q

How does the double bond in alkenes affect rotation?

A

Restricts rotation

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

Pi bond definition

A

The sideways overlap of 2 atomic orbitals above and below the two bonded atoms

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

Stereoisomer definition

A

Compounds with the same structural formula but with a different arrangement of the atom in space

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

What are the 2 types of stereoisomerism?

A
  1. E/Z isomerism

2. Optical isomerism

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

What is the criteria for E/Z isomerism?

A
  1. Molecule must contain a double bond which restricts movement
  2. Both carbons attached in the double bond must have 2 different groups attached to them
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How are priority groups determined?

A

The atom with the highest atomic number is the priority group

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

What is an E isomer?

A

Where the priority groups are on different sides of the C=C double bond

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

What is a Z isomer?

A

Where the priority groups are on the same side of the C=C double bond

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

What is cis-trans isomerism?

A

Where one group on each carbon in the double bond is the same

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

When do you have cis isomerism?

A

When the same group is on the same side

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

When do you have trans isomerism?

A

When the same group is on the opposite side

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

What is the conversion of hydrogenation?

A

Alkene –> alkane

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

What is the reagent for hydrogenation?

A

H2

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

What are the conditions for hydrogenation?

A

Nickel catalyst

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the conversion for hydration?

A

Alkene –> alcohol

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

What is the reagent for hydration?

A

Steam

17
Q

What are the conditions for hydration?

A

H3PO4 catalyst

18
Q

What is the conversion for addition halogenation?

A

Alkene –> haloalkane

19
Q

What is the reagent for addition halogenation?

A

Halogen/hydrogen halide (HCl)

20
Q

What are the conditions for addition halogenation?

A

Room temperature

21
Q

What are the 3 reactions for alkenes?

A

Hydrogenation, hydration and addition halogenation

22
Q

What is the test for alkenes?

A

Add bromine water, the solution will change from orange to colourless

23
Q

What does a curly arrow represent?

A

The movement of a pair of electrons

24
Q

What is an electrophile?

A

An electron pair acceptor

25
Q

What are the first 4 steps in electrophilic addition?

A
  1. The slightly positive H in polar HBr is attracted to the the electron-rich pi bond
  2. Pi bond breaks and it’s electron pair is donated to H atom in HBr
  3. Covalent bond forms between a C from the double bond and the H
  4. H-Br bond breaks by heterolytic fission
26
Q

What does the addition of a hydrogen halide/water to an ASYMMETRIC alkene make?

A

Two isomeric products

27
Q

What is an asymmetric alkene?

A

Where the 2 sides of the double bond are different (e.g. one carbon gas 2 H groups, the other carbon has CH3 and H)

28
Q

What is a carbocation?

A

Positive carbon

29
Q

What are primary, secondary and tertiary carbocations?

A

Primary - 0 or 1 alkyl group attached to carbocation

Secondary - 2 alkyl groups attached

Tertiary - 3 alkyl groups attached

30
Q

What changes from primary to tertiary carbocations?

A

Stability increases

31
Q

What is a major product?

A

The major product (the one that’s made more) forms via the most stable carbocation intermediate