C9 - Crude oil and fuels Flashcards
(20 cards)
What is a hydrocarbon?
A compound containing hydrogen and carbon only
How is crude oil formed?
Over millions of years from the remains of ancient biomass
What are alkanes?
Hydrocarbons with only single bonds
What are the first 4 alkanes?
Methane, ethane, propane, butane
What is the general formula for alkanes?
CnH2n+2
What does chain length do to boiling point?
The longer the chain, the higher the boiling point
What does chain length do to viscosity?
The longer the chain, the more viscous
What does chain length do to flammability?
The longer the chain, the lower the flammability
How can different alkanes in crude oil be separated?
Fractional distillation
What is a fraction?
A group of hydrocarbons with similar chain lengths
Name a useful fuel of fractional distillation
Petrol, diesel oil, kerosene
Name a useful material from crude oil fractions
Solvents, lubricants, polymers, detergents
What is complete combustion?
Burning of fuels in an excess of oxygen, producing water and carbon dioxide
What is incomplete combustion?
Burning of fuels when there’s not enough oxygen. It produces carbon monoxide
What is cracking?
Breaking down a hydrocarbon with a long chain into smaller molecules
What are the two types of cracking?
Steam and catalytic
What are alkenes?
Hydrocarbons with a double bond
What are alkenes used for?
Formation of polymers
Compare the reactivity of alkenes and alkanes?
Alkenes are more reactive
How can you test for alkenes?
Alkenes turn bromine water orange —> colourless
