Fuels and the enviroment Flashcards
revise
What are 3 examples of a fuel?
-Coal
-Oil
-Gas
What is a fuel?
Materials such as coal gas or oil that is burned to produce heat or power.
A substance that burns (combusts) in oxygen to produce energy
Why are fossil fuels called fossil fuels?
Because they are formed from fossilized/dead plant and animal matter over millions of years.
Describe the appearance of coal
Layered, thick
Black solid rock
What is the role of coal in electricity production?
The heat produced by the burning coal is used to turn water into steam. The steam passes through a turbine at very high pressure, causing the turbine to rotate very quickly. This allows the generator to generate electricity.
DIAGRAM- PAGE 3
What are the energy changes involved in electricity production?
heat = coal burning
kinetic = turbine rotating
electricity = generator
How was coal formed?
Millions of years ago, plants and trees in swamps died and, over time, were covered in layers of mud and water. The conditions were anaerobic, meaning no oxygen was present, meaning they couldn’t biodegrade naturally. Over millions of years layers of mud and rock built up. Huge pressure and high temperature turned plant remains into coal.
What does crude oil look like and what is it?
Black, brown or amber liquid, thick and sticky.
The oil when it is first extracted from the ground with all its impurities.
What are the main uses of crude oil?
-propel vehicles (fuel)
-heat buildings
-produce electricity
-power machinery
-plastics
-beauty
-agriculture
What is the difference between the way oil and coal is formed?
Oil is made with the remains of animals/sea creatures.
Coal is made from dead plants.
What is the process ‘refining’?
When oil is extracted from underneath the ground and split up into its useful components.
(take out the impurities)
What are the useful components of oil?
-petrol
-diesel
What molecules make up oil and what are they?
HYDROCARBONS
1 carbon atom
Multiple hydrogen atoms
What is meant by the term HYDROCARBON?
The compounds contain only elements hydrogen and carbon in them.
In what ways do hydrocarbons in crude oil differ?
They are varying lengths.
Some of the molecules have few hydrogens and carbons, others can have hundreds.
When hydrocarbons are split into groups due to refining what are they called?
The hydrocarbons get separated into similarly sized hydrocarbon molecules in groups. Each group is called a FRACTION.
What does a PETROL FRACTION consist of?
6-8 carbon atoms
What means if there is a lot of carbon in a chain?
The longer the chain.
Higher viscosity.
What is the process of refining when crude oil is separated into its different components of fractions?
FRACTIONAL DISTILLATION
Separating crude oil into its fractions based on their different boiling points.
Why are hydrocarbons able to be separated with fractional distillation?
The longer the chain, the higher the boiling point.
NUMBER OF CARBONS DEFINE BOILING POINT.
What is ‘cracking’?
Taking long chain hydrocarbons and making them smaller, more useful molecules.
What makes a good fuel?
-Burns efficiently
-Burns for a long time
-Provides a lot of energy
-Inexpensive
-Readily available - good supply
Out of ethanol, propanol and butanol which is the ‘best’?
Butanol, because it has the highest temperature rise per gram.
What are the products when you burn hydrocarbons?
water
carbon dioxide
In the combustion experiment, why it was it necessary to have a u tube submerged in cold water?
To cause condensation, and the cold water cools down the liquid vapours.
What does CO2 do?
INCREASES TEMPERATURE
What is the word equation for the combustion of a hydrocarbon?
hydrocarbon + oxygen – carbon dioxide + water
