C9 crude oil Flashcards
What is the general formula for an Alkane
CnH2n+2
Why are alkanes described as saturated?
Each carbon contains as many hydrogen atoms as possible.
What are most of the compounds in crude oil?
Hydrocarbons
What are the properties of a long chain hydrocarbon
-Higher viscocity(Thickness)
-Lower volatility(ability to change into a gas)
-Higher Boiling point
-Lower flammability
What process is used to seperate crude oil?
Fractional Distillation
Where are the shorter chain hydrocarbons usually refined in the fractionating column?
Near the top
What is complete combustion?
Burning in a excess of oxygen. Complete combustion of a hydrocarbon produces water vapour and carbon dioxide.An indicator would be a clean blue flame.
What is incomplete combustion?
Incomplete combustion happens when the supply of air or oxygen is poor. Water is still produced, but carbon monoxide and carbon are produced. Less energy is released than during complete combustion.
What is cracking?
The breaking down of large alkanes molecules into smaller more useful hydrocarbon molecules such as 1 alkane and 1 or more alkenes by vaporising them and passing them over a hot catalyst.
What are the 2 methods of cracking?
Catalytic cracking uses a temperature of approximately 550°C and a
catalyst
known as a zeolite which contains aluminium oxide and silicon oxide
Steam cracking uses a higher temperature of over 800°C and no catalyst
Why is cracking important?
It helps to match the supply of fractions with the demand for them.
It produces alkenes, which are useful as
feedstock for the petrochemical industry.
What are the differences between alkenes and alkanes?
alkanes are saturated, their carbon atoms are only joined by C-C single bonds
alkenes are unsaturated, they contain at least one C=C double bond
What is a test for alkenes?
Orange bromine water turns colourless in the presence of alkenes.
