Brainscape's Knowledge GenomeTM

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


See full index

AQA Chemistry Separate Science > 6. Crude OIl and hydrocarbons > Flashcards

6. Crude OIl and hydrocarbons Flashcards

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

How is crude oil formed?

A

Millions of years ago marine (sea) creatures died and fell to the bottom of the oceans.
Layers of other creatures and sediment built up on top.
The layers of died marine creatures were heated and compressed and eventually turned into oil and gas.

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

What is a definition of crude oil?

A

Mixture

of mostly hydrocarbons

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

What is the definition of a hydrocarbon?

A

A compound that contains hydrogen and carbon atoms only.

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

What is a homologous series?

A

A group of different compounds with similar structures or functional groups.

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

What is the general formula for the alkane homologous series?

A

CnH2n+2

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

What can be said about alkanes?

A

They only contain hydrogen and carbon.
All the bonds are single bonds
They are saturated compounds
They have the general formula CnH2n+2

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

What are the first for alkanes in the homologous series?

A

Methane - 1
Ethane - 2
Propane - 3
Butane - 4

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

What are the molecular, structural and empirical formulae of propane?

A

molecular - C3H8
structural - CH3Ch2CH3
empirical formulae - C3H8

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

What are the molecular, structural and empirical formulae of butane?

A

molecular - C4H10
structural - CH3CH2CH2CH3
empirical formulae - C2H5

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

What is the name of the process by which crude oil is separated?

A

Fractional distillation

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

How does fractional distillation work?

A

The crude oil is heated (to around 350 oC)
As the mixture rises up the fractionating column it cools.
The longer the carbon chain length the higher the boiling point.
Longer chains condense lower down the fractionating column.
Different fractions of the mixture are isolated/removed/produced at different heights in the fractionating column.

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

What is the trend of boiling and melting point as chain length increases?

A

The longer the chain the higher the boiling and melting point.

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

What is meant by the term chain length?

A

The number of carbon atoms present in single unbroken line of the hydrocarbon.

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

Why does the boiling and melting point increase as chain length increases?

A

There are more intermolecular forces between individual molecules as the chain length increases.

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

What is the trend of flammability as chain length increases?

A

Flammability decreases as chain length increases.

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

What is the trend of viscosity as chain length increases?

A

Viscosity is the resistance to flow

it increases

17
Q

What is the trend of cleanliness of the flame as chain length increases?

A

Cleanliness decreases as chain length increases.

18
Q

Name some of the key fractions produced from crude oil.

A 
Refinery gas
Petrol
Kerosene
Heavy fuel oil
Bitumen
19
Q

What is cracking?

A

Where longer chain hydrocarbons are broken down into short chain ones?

20
Q

What are the conditions for cracking?

A

Catalytic cracking - catalyst and high temperature

Steam cracking - water vapour and high temperature

21
Q

Why is cracking useful?

A

There is more demand for shorter chain hydrocarbons than the percentage of those fractions.
There is less demand for longer chain hydrocarbons than the percentage of those fractions.
Converts less useful into more useful hydrocarbons.

22
Q

What is produced in cracking?

A

A variety of saturated (alkanes) and unsaturated (alkenes) hydrocarbons.

23
Q

What are alkenes?

A

Hydrocarbons with one or more double carbon bond.

24
Q

What are unsaturated hydrocarbons?

A

Hydrocarbons with one or more double or triple carbon bond.

25
Q

What are the similarities between alkanes and alkenes?

A

Both:
Hydrocarbons containing hydrogen and carbon only.
Combust to form carbon dioxide and water

26
Q

What are the differences between alkanes and alkenes?

A

Alkenes are more reactive
Alkenes are unsaturated; Alkanes are saturated
Alkenes can produce polymers
Alkenes have a double bond; alkanes only have single bonds

AQA Chemistry Separate Science (8 decks)

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