Crude oil

Question 1

What is crude oil separated into?

Answer 1

Hydrocarbon fractions

Question 2

What are hydrocarbons?

Answer 2

Molecules which are made of only carbon and hydrogen

Question 3

How are the different compounds in crude oil separated?

Answer 3

By fractional distillation

Question 4

How does a fractionating column work?

Answer 4

The crude oil is heated until most of it is gas (bottled gas)
The liquid, bitumens, is drained off.

Question 5

What is the temperature in a fractionating column?

Answer 5

Hotter at the bottom (340°) and it gets progressively cooler towards the top (40°)

Question 6

In a fractionating column, when does each substance condense?

Answer 6

When the substances reach a part of the column where the temperature is lower than their boiling point they condense

Question 7

Do long hydrocarbons have low or high boiling points

Answer 7

High boiling points

Question 8

Where in the fractionating column do longer hydrocarbons condense?

Answer 8

They condensed and drain out of the column earlier on, near the bottom

Question 9

Where in the fractionating column do shorter hydrocarbons condense?

Answer 9

They condensed and drain out of the column later on, near the top

Question 10

What do bubble caps do in the fractionating column?

Answer 10

Stop separated liquids from remixing

Question 11

What is crude oil mixture separated into?

Answer 11

Different fractions

Question 12

What do the hydrocarbons in each fraction have in common?

Answer 12

Similar boiling points

Question 13

Does each fraction contain saturated or unsaturated hydrocarbons?

Answer 13

Both saturated and unsaturated

Question 14

What type of bonds do saturated hydrocarbons have?

Answer 14

Single bonds

Question 15

What type of bonds do unsaturated hydrocarbons have?

Answer 15

Double or triple bonds

Question 16

Name some fractions tapped off a fractionating column

Answer 16

Refinery gas
Petrol
Naphtha
Kerosene
Diesel
Oil
Bitumen

Question 17

What are alkanes?

Answer 17

Saturated hydrocarbons

Question 18

What is the general alkane formula?

Answer 18

CnH2n+2

Question 19

What are the first five alkanes?

Answer 19

Methane
Ethane
Propane
Butane
Pentane

Question 20

Where do alkanes burn?

Answer 20

In combustion reactions

Question 21

What makes up the majority of hydrocarbons in crude oil?

Answer 21

Alkanes

Question 22

What do alkanes need in order to combust?

Answer 22

A good supply of oxygen

Question 23

What is made when halogens react with alkanes?

Answer 23

Haloalkanes

Question 24

What is released when you burn a fuel?

Answer 24

Energy in the form of heat

Question 25

Give a reason why hydrocarbons make great fuels

Answer 25

They combust when you burn them in oxygen

Question 26

What is the formula for complete combustion?

Answer 26

Hydrocarbon + oxygen —> carbon dioxide + water

Question 27

What is cracking?

Answer 27

Splitting up long chain hydrocarbons A form of thermal decomposition

Question 28

Name two features of long hydrocarbons

Answer 28

High boiling points Viscous

Question 29

Name two features of shorter hydrocarbons

Answer 29

Low boiling points Thinner and paler in colour

Question 30

is the demand higher for short chain hydrocarbons or long chain hydrocarbons?

Answer 30

Short chain hydrocarbons like octane found in petrol

Question 31

What are long chain hydrocarbon split into?

Answer 31

More useful molecules

Question 32

What does cracking produce?

Answer 32

Alkanes which are used to make polymers

Question 33

What conditions are needed for cracking?

Answer 33

Heat, plus a catalyst

Question 34

In industry, at what temperature are vaporised hydrocarbons passed over a powdered catalyst?

Answer 34

600°-700° C

Question 35

Give two examples of a catalyst used in cracking?

Answer 35

Silica SiO2 Alumina Al2O3