Crude Oil

Question 1

Main information about crude oil

Answer 1

Type of fossil fuel
Finite resource
Formed by plankton buried in mud for millions of years
Time and pressure

Question 2

What is crude oil a mix of

Answer 2

Hydrocarbons

Question 3

What are hydrocarbons

Answer 3

Only hydrogen and carbon
C and H atoms joined by covalent bonds to form a homologous family called alkanes

Question 4

What are alkanes

Answer 4

Hydrogen molecules with single covalent bonds between carbon atoms
Saturated
Used as fuels

Question 5

General formula for alkanes

Answer 5

CnH2n+2 (n=number of carbons)

Question 6

Name the first five alkanes and give their molecular formula

And give names of the next five

Answer 6

Methane CH4
Ethane C2H6
Propane C3H8
Butane C4H10
Pentane C5H12
Hexane
Heptane
Octane
Nonane
Decane

Question 7

How many carbons does petrol have

Answer 7

6-10

Question 8

What are alkenes

Answer 8

Another homologous family of hydrocarbon molecules with a double C=C bond
Unsaturated
Used as plastics

Question 9

General formula for alkenes

Answer 9

CnH2n

Question 10

Properties if the chain length in longer (more hydrocarbons)

Answer 10

Higher boiling point, less volatile, less flammable, high viscosity

Question 11

Properties of the shorter chain length

Answer 11

Lower boiling point, more flammable, low viscosity, very volatile

Question 12

What is viscosity?

Answer 12

How easily it flows

Question 13

What is volatility?

Answer 13

Tendency to turn into gas

Question 14

What’s a fraction?

Answer 14

Specific length carbon chain within the crude oil mixture

Question 15

Effect of chain length on intermolecular forces

Answer 15

A longer chain length has more intermolecular forces so for example has a higher boiling point as it requires more energy to break them apart

Question 16

What’s the products of complete combustion

Answer 16

Carbon dioxide and water

Question 17

What’s the products of incomplete combustion (insufficient oxygen)

Answer 17

Carbon monoxide & water

Question 18

What happens to cobalt chloride paper in the presence of water?

Answer 18

Blue to pink

Question 19

What does the limewater test indicate when it turns cloudy?

Answer 19

The presence of carbon dioxide

Question 20

What is the function of the ice bath in the products of combustion experiment?

Answer 20

Condense water vapour from the combustion

Question 21

Describe the setup of the experiment to test the products of combustion.

Answer 21

A candle is burned under a funnel, and the gases produced pass through a U-tube placed in an ice bath. The U-tube contains cobalt chloride paper to test for water. The gases then move into a test tube with limewater to test for carbon dioxide.