Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Chemistry > 3.3.2-Alkanes > Flashcards

3.3.2-Alkanes Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Chemistry flashcards Periodic Table flashcards Chemistry 101 flashcards Organic Chemistry 101 flashcards
1
Q

What is petroleum

A

It is a complex mixture of hydrocarbons

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

2 features of petroleum

A

Mainly alkanes which are hydrocarbons

When first extracted is almost useless

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

How is petroleum separated

A

Fractional distillation

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

3 key points of fractional distillation

A

Relies on hydrocarbon chains length being different so bp are different

Long chains have higher boiling point than short Chains

Long chains move toward bottom and short chains to top

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

Uses of fractions

A

Fuels
Petrochemicals
Feedstock for cracking

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

Why do we do cracking

A

There are a shortage of some chain length and a surplus of others as well alkenes are in high demand to make polymer which can only be found through cracking

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

What does a high mr make after cracking

A

Small mr + alkenes + hydrogen

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

What are the conditions of thermal cracking

A

High temperature 400-600

High pressure (7,000Kpa)

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

What are the products of thermal cracking

A

Alkenes

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

What are the uses of the products from thermal cracking

A

Chemical feedstock and conversion to polymers

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

Thermal cracking
Conditions
Products
Uses

A

High temperature
High pressure

Alkenes

Chemical feedstock and conversion to polymers

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

Catalytic cracking

Conditions

A

High temp -450
Slight pressure
Zeolite catalyst

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

Products of catalytic cracking

A

Branched alkanes, cyclohexane, aromatic hydrocarbons

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

Uses of products of catalytic cracking

A

Motor fuels

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

Methane use when burned

A

Natural gas, cooking , heating , electric

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

Combustion of propane uses

A

Camping fuel , domestic fuel and industrial fuel

17
Q

Combustion of butane uses

A

Camping fuel and lighters

18
Q

Uses of octane combustion

A

In petrol

19
Q

What is complete combustion conditions and products

A

Excess of oxygen

Products CO2 and H20

20
Q

What are conditions and products of incomplete combustion

A

Limited supply of oxygen
Products CO,C and H2O

CO is poisonous

21
Q

What are the the pollutant produced by car engines

A

CO

NOx

Unburnt hydrocarbons

22
Q

How is Co formed and the problem

A

Incomplete combustion

Poisonous gas

23
Q

How are NOx formed and the problem

A

N2 and O2 react at high temperatures in engine

Combine with water to make acid rain and chemical smog

24
Q

How NOx forms acid rain equation

A

4NO+O2+H2O - HNO3

25
Q

How does NOx form chemical smog equation

A

4NO+O2+2H2O - 4HNO3

26
Q

How are unburnt hydrocarbons formed and the problem

A

Engine not hot enough

Makes photochemical smog irritating to lungs

27
Q

What is a catalytic converter

A

Catalytic converters are honeycomb of ceramic material coated with catalytic metals in thin layers

28
Q

Examples of catalysts

A

Platinum, palladium , rhodium

29
Q

How is NOx and CO changed to harmless gas in catalytic converter

A

NOx
C

Adsorb onto catalyst and react to form N2 and CO2

2NO+2CO- N2 +2CO2
NO2 +4CO - N2 + 4CO2

30
Q

How do unburnt hydrocarbons change to unharmful compounds

A

React with NO to produce CO2 and H20 and N2

C8H18+25NO-8CO2+9H2O+12.5H2O

31
Q

What happens when fossil fuels contain sulphur

A

S+O2 burns to make SO2

This goes into the air

32
Q

What is the problem with SO2

A

SO2 in the air with water forms H2SO3 which is acid rain

33
Q

How do you remove SO2

A

FGD(flue gas desulphisers)

Passed through CaO
SO2+ CaO–CaSO3
Oxidised
CaSO3+1/2O2 – CaSO4

34
Q

How can CaSO4 be used after it is formed

A

Can be used as gypsum in plaster

35
Q

What are the greenhouse gases

A

Carbon dioxide
Methane
Water

36
Q

What do the greenhouse gases do

A

Absorb some of infa-red energy
Molecules then emit energy in all directions
Some returns to surface to keep warm

37
Q

Impact of global warming

A

Ice in polar regions are melting and retreating

Sea levels rising

Chemistry (29 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions