Chapter 9 - Chemistry Flashcards
What is crude oil?
Crude oil is a mixture of many different compounds.
What are most of the compound in crude oil?
They are hydrocarbons - they contain only hydrogen and carbon atoms.
What are alkanes?
They are saturated hydrocarbons, they contain as many hydrogen atoms as possible in their molecules
How is crude oil separated?
It is separated into fractions, using fractional distillation.
What do the properties of each fraction depend on?
The size of the hydrocarbon molecules in it.
Why do lighter fractions make better fuels?
As they ignite more easily and burn well, with cleaner (less smoky) flames
What happens when hydrocarbon fuels are burned in plenty of air?
The carbon and hydrogen in the fuel are completely oxidised. They produce carbon dioxide and water.
What does incomplete combustion of a hydrocarbon produce?
It produces carbon monoxide (a toxic gas) as one of it’s products
How can large hydrocarbon molecules be broken up into smaller molecules?
By passing the vapours over a hot catalyst, by mixing them with steam and heating them to a very high temperature.
What does cracking produce?
Saturated hydrocarbons (called alkanes)
What do alkanes and other unsaturated compounds containing carbon double bonds react with?
They react with orange bromine water, turning it colourless
