Unit 10: Fuels & Earth and Atmospheric Science Flashcards
What are hydrocarbons? (2 mark)
Compounds that contain only hydrogen and carbon atoms
What is crude oil?
- Complex mixture of hydrocarbons
- An important source of useful substances
- A finite resource
What are some important fossil fuels obtained from crude oil?
- Petrol
- Kerosene
- Diesel Oil
- Bitumen
- Fuel Oil
Explain why crude oil is a finite resource (3 mark)
Crude oil takes a long time to be produced, and the rate at which humans are using it is too high for it to replenish, (demand is higher than the supply) so it is therefore non-renewable and not infinite
What state is crude oil in at room temperature?
Liquid
What does fractional distillation do to crude oil?
It separates crude oil into simpler, more useful mixtures that we use in our day to day life
Name the substances obtained from fractional distillation of crude oil
- Gases
- Kerosene
- Diesel Oil
- Fuel Oil
- Bitumen
What is the fraction of gases used for?
Domestic heating and cooking
What is the fraction of petrol used for?
Fuel for cars
What is the fraction of kerosene used for?
Fuel for aircrafts
What is the fraction of diesel oil used for?
Some cars, and trains
What is the fraction of fuel oil used for?
Fuel for large ships and in some power stations
What is the fraction of bitumen used for?
To surface roads and roofs
What does viscous mean?
Having a thick, sticky consistency between solid and liquid; having a high viscosity.
When something has a low viscosity, it flows easily
If I describe something as extremely volatile, what do I mean?
That it is easy to ignite
If I describe something as not very volatile, what do I mean?
That it is not easy to ignite
How does fractional distillation differ from distillation?
It differs from distillation only in that it separates a mixture into a number of different parts, called fractions
How does fractional distillation work?
- A tall column is fitted above the mixture, with several condensers coming off at different heights
- The column is hot at the bottom and cool at the top (it is heated from the bottom)
- Substances with high boiling points condense at the bottom, and substances with low boiling points condense at the top
- This works because different substances in the mixture have different boiling points
What are the properties of the gases at the top of the column?
- More Volatile
- Less Viscous
- Shortest Chain
- Lowest Boiling Point
- Easy to Ignite
What are the properties of the gases at the bottom of the column?
- More Viscous
- Less Volatile
- Longer Chain Length
- Higher Boiling Point
- Harder to ignite
What fraction has the lowest boiling point?
Gases
What fraction has the highest boiling point?
Bitumen
Which fraction has a boiling point between those of Gases and Kerosene?
Petrol
What fraction has a boiling point between those of Petrol and Diesel?
Kerosene
What fraction has a boiling point between those of Kerosene and Fuel Oil?
Diesel
What fraction has a boiling point between those of Diesel and Bitumen?
Fuel Oil
Explain how petrol and bitumen differ in their properties and uses? (6 Mark)
Properties:
- Petrol has a shorter chain length (or opp.)
- Petrol has lower boiling point (or opp.)
- Petrol has lower viscosity (or opp.)
- Petrol ignites/burns very quickly (or opp.)
- Bitumen does not combust completely due to high number of carbon atoms per molecule
- Burning Bitumen produces a lot of Carbon Monoxide & Soot
Uses:
Petrol: Fuel in cars/motorbikes/transportation
Bitumen: Used in surfacing roads/used for roofing/flooring
What is the molecular formula for Ethane?
C2H6