Crude Oils Flashcards
1
Q
Describe crude oil
A
- find in rocks
- finite resource
= will one day run out - mixture of hydrocarbons
2
Q
Alkane general formula
A
CnH2n+2
3
Q
Describe alkanes
A
- saturated molecules
= as carbon atoms are fully bonded to hydrogen atoms
4
Q
Define viscosity
A
= tells us the thickness of a fluid
- fluid with high “ flow slowly
= eg honey
5
Q
Properties of hydrocarbons
A
- short chain hydrocarbons are extremely flammable
- as size of hydrocarbon molecules increase, molecules get less flammable
- long chain are hard to burn
- short chain have low boiling points
6
Q
Describe hydrocarbon fuels
A
- release energy when combusted
- during combustion carbon and hydrogen atoms in fuel react with oxygen
= carbon and hydrogen oxidised
7
Q
Describe fractional distillation
A
- crude oil heated to high temp
- crude oil boils
- crude oil vapour fed into the fractional distillation column
- column is hotter at bottom and cooler at the top
- hydrocarbon vapours rise up column
- hydrocarbons condense when they reach their boiling point
- liquid fractions then removed
- remaining hydro sobs move up column
- these condense when reached boiling points
- very long chain hydrocarbons Hav high boiling points
= removed from bottom on column
8
Q
Why aren’t long chain hydrocarbons good fuels
A
Aren’t very flammable
9
Q
How is crude oil formed
A
- found in remains of dead plant or animals that are burried in mud
- high pressures and temperatures of ground turned organic biomass into crude oil
- as it formed it soaked into rocks and stored for millions of years
10
Q
Describe fractional distillation
A
- heat crude oil and separate compounds depending on different boiling points
11
Q
Steps of fractional distillation
A
- heat oil until turned into gas
- pass gas into fractioning column which is hot at the bottom
- hot gases rise up column
- once reaches region of boiling point it will condense and turn into liquid
- long chain hydrocarbons have highest boiling points
= quickly condense into liquid and drain out of column early on
= as not hot enough to stay a gas - some hydrocarbons stay as gas entire time
12
Q
Describe shorter chain hydrocarbons
A
Most flammable
= best fuels
13
Q
Describe long chain hydrocarbons
A
Can be broken down into small hydrocarbons in cracking
14
Q
Example of long chain hydrocarbons
A
Bitumen
15
Q
Example of shorter chain hydrocarbons
A
Petrol
Dorsal
Kerosene
Butane
