Crude Oil, Hydrocarbons, Alkenes/anes

Question 1

What is crude oil?

Answer 1

A finite recourse (fossil fuel) found in rocks that’s a mixture of compounds that are mostly hydrocarbons

Question 2

How is crude oil separated?

Answer 2

Fractional distillation

Question 3

Uses for crude oil

Answer 3

Transport, heating and fuel

Question 4

Explain fractional distillation process

Answer 4

Oil heated to 370°c and evaporates. Gas into fractionating column. Longest hydrocarbons = highest bp = condense first at bottom.

Question 5

What is fractional distillation

Answer 5

It separates hydrocarbons in a mixture by their boiling points

Question 6

Example of a long hydrocarbon fuel

Answer 6

Heavy fuel oil

Question 7

Explain the temperature gradient of the fractionating column

Answer 7

Hot to cold gradient. Bottom = hottest.

Question 8

Define hydrocarbon

Answer 8

Compound containing only carbon and hydrogen atoms

Question 9

What are the properties of a hydrocarbon?

Answer 9

Depends on chain length: shorter = less viscous, more volatile and more flammable

Question 10

Flammability of hydrocarbons

Answer 10

Shorter = more flammable

Question 11

Viscosity of hydrocarbons

Answer 11

Shorter = less viscous

Question 12

Volatile (boiling points) of hydrocarbons

Answer 12

Shorter = more volatile = lower boiling point

Question 13

Equation of complete combustion of hydrocarbons

Answer 13

Hydrocarbon + oxygen -> co2 + water + energy
(Carbon and hydrogen are oxidised)

Question 14

What are alkanes?

Answer 14

Hydrocarbons with similar chemical properties, joined by single bonds

Question 15

Formula for alkanes

Answer 15

CnH2n+2

Question 16

First 4 alkanes

Answer 16

Methane, ethane, propane, butane.

Question 17

Methane formula

Answer 17

CH4

Question 18

Ethane formula

Answer 18

C2H6

Question 19

Propane

Answer 19

C3H8

Question 20

Butane formula

Answer 20

C4H10

Question 21

Alkenes formula

Answer 21

CnH2n

Question 22

Define alkenes

Answer 22

Hydrocarbons with a double carbon bond

Question 23

Are alkenes saturated?

Answer 23

No unsaturated because there are two fewer hydrogen atoms

Question 24

Are alkenes or alkanes more reactive?

Answer 24

Alkenes are more reactive

Question 25

Name first 4 alkenes

Answer 25

Ethane, propane, butene, pentene

Question 26

Ethene formula

Answer 26

C2H4

Question 27

Propene formula

Answer 27

C3H6

Question 28

Butene formula

Answer 28

C4H8

Question 29

What is cracking?

Answer 29

The splitting of long chain hydrocarbons in thermal decomposition. Either by catalytic or steam.

Question 30

What is steam cracking?

Answer 30

800°c without a catalyst

Question 31

What is catalytic cracking?

Answer 31

550°c with a catalyst

Question 32

What are differences between ethene and ethane?

Answer 32

Ethene can form polymers, more reactive, double c-c bond, unsaturated, turn bromine water colourless
Both simple molecules and use covalent bonds

Question 33

Effect of alkenes on bromine water

Answer 33

Orange -> colourless

Question 34

Effect of alkanes on bromine water

Answer 34

No effect. Liquid remains orange.

Question 35

What are the products of hydrocarbons complete combustion?

Answer 35

CO2 and water