C9- Crude oil and fuels

Question 1

Crude oil def?
How is it extracted?
Made of what?
Source of what?

Answer 1

A mixture made from remains of biomass from microscopic organisms (algae and plankton)
Drilling
Different hydrocarbons
Petrol and diesel fuel

Question 2

How was crude oil made?

Answer 2

Layers of rock, creating high pressure and temperature, lack of oxygen

Question 3

Hydrocarbon

Answer 3

A compound that contains only hydrogen and carbon atoms

Question 4

How to make crude oil useful?

Answer 4

Fractional distillation to separate the substances

Question 5

What are alkanes?
What mainly consists of alkanes?

Answer 5

Saturated hydrocarbons, contain maximum number of hydrogen atoms
Crude oil

Question 6

What do straight lines in alkanes represent?
General formula for alkane molecules?

Answer 6

Single covalent bonds
CnH 2n+2

Question 7

First 6 alkanes?

Answer 7

Methane
Ethane
Propane
Butane
Pentane
Hexane

Question 8

Alkane state at room temp depends on..?
Why?

Answer 8

Depends on intermolecular forces
Bigger forces, higher boiling point

Question 9

Smaller chains of hydrocarbons
Boiling point?
Volatility?
Viscosity?
Flammability?

Answer 9

Lower, weak intermolecular forces, need less energy to overcome
High volatility- turns into gas easily
Low viscosity, very runny
Highly flammable

Question 9

Larger chains of hydrocarbons?
Boiling point?
Volatility?
Viscosity?
Flammability?

Answer 9

Higher, stronger intermolecular forces, more energy to overcome
Low volatility
High viscosity
Lower flammability

Question 10

How is crude oil separated?
Into what and its def?

Answer 10

Fractional distillation
Fractions- groups which have similar boiling points

Question 11

Describe the process of fractional distillation of crude oil

Answer 11

Crude oil heated at around 350 oc, fed into fractionating column as vapour, some is drawn off as a liquid at bottom
Vapours rise until they reach their boiling point, then cool and condense
These fractions collected as a liquid
Hydrocarbons with lowest boiling points move to top of column where coolest

Question 12

What are the products of complete combustion of a hydrocarbon?
What does incomplete combustion of a hydrocarbon produce?

Answer 12

Carbon dioxide and water

Carbon monoxide

Question 13

How to test the products of complete combustion of a hydrocarbon?

Answer 13

Gas produced from flame, travels through ice bath where the water turns blue cobalt chloride paper pink, and condenses due to ice.
Gas then bubbled through limewater, where carbon dioxide turns it cloudy

Question 14

Complete combustion…
Oxygen?
More likely in?
H atoms become?
C atoms become?
Products cause?

Answer 14

Enough oxygen
Small alkanes and blue bunsen flame
Water
Carbon dioxide
Contributes to climate change

Question 15

Incomplete combustion
Oxygen?
More likely in?
H atoms become?
C atoms become?
Products cause?

Answer 15

Not enough oxygen
Large alkanes and yellow bunsen flame
Water
Carbon monoxide or carbon (soot)
Carbon monoxide is toxic, carbon causes lung disease

Question 16

How to work out… in combustion of hydrocarbon equation?
CO2 atoms?
H2O atoms?
O2 atoms?

Answer 16

CO2= number of C atoms in hydrocarbon
H2O= CO2 +1
O2= CO2 + (1/2 x H2O)

Question 17

What is cracking?
What type of reaction is it?

Answer 17

Process of breaking down long hydrocarbons into shorter more useful ones like, alkanes and alkenes
Thermal decomposition

Question 18

General formula for alkenes?
How to tell alkenes?

Answer 18

CnH2n
Unsaturated, contains double bond between C atoms

Question 19

How to test for an unsaturated hydrocarbon?

Answer 19

Bromine solution will turn from orange to colourless

Question 20

Difference between thermal and catalytic cracking

Answer 20

Thermal- high temp and pressure
Catalytic- low temp and pressure

Question 21

Thermal cracking
Takes place in?
Temp?
Pressure?
Catalyst?

Answer 21

Industry
450-750oc
70 atm
None

Question 22

Catalytic cracking industry?
Temp?
Pressure?
Catalyst?

Answer 22

500oc
1atm
Zeolites

Question 23

Catalytic cracking laboratory?
Temp?
Pressure?
Catalyst?

Answer 23

Bunsen flame
1 atm
Broken crockery, pumice stone