Halogenoalkanes Flashcards

1
Q

what do halogenoalkanes have?

A

different rates of substitution

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

What are the bond energies for different halo-alkanes?

A

c-f is the strongest bond
c-i is the weakest bond

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

what will reacting halogenoalkanes with aqueous silver nitrate result in?

A

chlorides make white precipitate of silver chloride. bromides make a cream precipitate of silver bromide. iodides make a pale yellow precipitate of silver iodie

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

which precipitate formation is the fastest and the slowest?

A

the formation of the pale yellow silver iodide is the fastest(fastest nucleophilic substitution reaction) (most reactive) whereas the formation of the silver fluoride isthe slowest (least reactive

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

define a primary haloalkane

A

has one alkyl group attached to the carbon with the halogen atoms eg 2-bromobutane

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

define a secondary halo alkane

A

has two alkyl groups attached to the carbon with the halogen atom

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

define a tertiary halo alkane

A

has three alkyl groups attached to carbon atom with the halogen atom

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

why is the c-h bond in a halo-alkane said to be polar?

A

it has a permanent dipole

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

what states are halo alkanes at room temp and pressure?

A

liquid or gases. the bpt is dependant on the IMF that operate

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

what happens to halo-alkanes bpt as the chain gets longer/bigger molecule?

A

the boiling point increases. the molecule is bigger so greater electronegativity and so greater van der waals forces

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

what happens to the bpt if the atomic mass/atom size increases?

A

the boiling point due to increases in the van der waals forces of attraction

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

What is nucleophilic substitution?

A

Reaction in which a molecule with a partial positive charge is attacked by a nucleophile and the replacement of a leaving group for example halogen by the nucleophile

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

What is a nucleophile?

A

Electron pair donor eg a hydroxide ion cyanide ion and ammonia

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

What is an intermediate?

A

In chemistry, a reactive intermediate is a short-lived highly reactive molecule. When generated in a chemical reaction, it will be quickly converted into a more stable molecule.

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

What does the arrows show?

A

Movement of electrons

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

What is the nucleophile attracted to?

A

Area of positivity

17
Q

What can the reagents for nucleophilic substitution be?

A

Hydroxide ions
Cyanide ions
Ammonia ions

18
Q

What can the reagents for elimination be?

A

Hydroxide ions

19
Q

What are the conditions for nucleophilic substitution with hydroxide ions?

A

Warm aqueous sodium hydroxide and ethanol
Reflux

20
Q

What are the conditions for nucleophilic substitution with cyanide ions?

A

Warm ethanolic potassium or sodium cyanide
Reflux

21
Q

What are the conditions for nucleophilic substitution with ammonia ions?

A

Heat with ethanolic ammonia
Use excess ammonia

22
Q

What are the conditions for the elimation reaction with hydroxide ions?

A

Warm ethanolic sodium or potassium hydroxide
Reflux

23
Q

What does primary secondary and tertiary halo alkanes favour? Substitution and Elimination

A

Primary- substitution
Secondary-both occur at the same time
Tertiary. - elimination

24
Q

What do higher temperatures favour in terms of substitution or elimination?

A

Favour elimination

25
Q

What does increasing base strength of the electron pair favour? Substitution and Elimination

A

Elimination favoured

26
Q

Can you alter conditions for secondary halo alkanes?

A

Secondary halogen alkanes you can alter the conditions to substitution or elimination. Substitution equals warm aqueous ethanol.
Elimination equals hot anhydrous ethanol

27
Q

How is ozone formed

A

Ozone is formed naturally from oxygen via photochemical reaction

28
Q

Why is ozone essential to life on earth.

A

Ozone is essential to life on Earth as it prevents harmful UV radiation from entering the earths atmosphere

29
Q

What would happen if ozone is reduced?

A

UV radiation will kill off plankton stunt to the growth of agricultural crops which will cause farming and then damage eyesight and cause skin cancer in humans