Topic 8 - Fuels And Earth Science Flashcards
What are hydrocarbons?
Compound that contains hydrogen and carbon atoms only
What is crude oil?
A complex mixture of hydrocarbons
Contains molecules with rings or chains of carbon atoms
An important source of useful substances like fuels and feedstocks for the petrochemical industry
A finite resource
Where can crude oil be found?
Under the sea and ground
What does it mean when crude oil is described as finite?
It will run out
How can crumped oil be separated?
Fractional distillation
How does the process of fractional distillation work to separate crude oil?
Crude oil is vaporised before it enters a fractionating column
The fractionating column is hotter at the bottom than at the top. The vapours rise up and condense at different fractions depending on their boiling points
Hydrocarbons with low boiling points will be tapped off the top of the column and hydrocarbons with high boiling points will be tapped off the bottom of the column
Why is crude oil separated?
Unseparated crude oil isn’t very useful but the separated products are very useful
Refinery gas is a fraction of crude oil. What are its common uses?
Heating and cooking
What fraction of crude oil is used as fuel in cars?
Petrol (gasoline)
Diesel is also less commonly used
Kerosene is a fraction of crude oil. What is common use of kerosene?
Aircraft fuel
Diesel oil is a fraction crude oil. What is it commonly used for?
Fuel for some cars and trains
Which fraction of crude oil is used for road surfacing and roofs?
Bitumen
Fuel oil is a fraction of crude oil. What is it commonly used for?
Fuel for large ships and in some power stations
How do the hydrocarbons at each faction differ?
Boiling points
Ease of ignition
Viscosity
The number of hydrogen and carbon atoms their molecules have
Where is the fractionating column do hydrocarbons with the highest viscosity condense?
They car collected at the bottom of the fractionating column
What are the properties of hydrocarbons that are tapped from the top of the fraction in column, like petrol and refinery gas?
Low boiling point
High volatile
Easily ignited
Shorter carbon chains
What is a homologous series?
Series of compounds which: Have the same general formula Have similar chemical properties Differ by CH2 in molecular formula form neighbouring molecules Slight variation in physical properties
Products from crude oil mostly belong to which homologous series?
Askance series
What are the only products when a hydrocarbon fuel undergoes complete combustion?
Water and carbon dioxide
Is energy given out when a fuel undergoes complete combustion?
Yes, it is exothermic