C1 4 Crude Oils and Fuels Flashcards
What are fractions?
Substances with similar boiling points.
What is crude oil?
A mixture of lots of different compounds.
Why is distillation used to separate the substances in crude oil?
As the properties of the substances do not change when they are mixed. It can be used to separate mixtures with different boiling points.
Briefly explain the process of distillation in crude oil.
The crude oil mixture is heated so that it boils. The different fractions vaporise in different temperatures and we collect the vapours by cooling and condensing them.
What are nearly all the compounds in crude oil?
Hydrocarbons
What are hydrocarbons?
Compounds containing only hydrogen and carbon.
What are most of the hydrocarbons in crude oil?
Alkanes
What are the first five alkanes?
Methane Ethane Propane Butane Pentane
What is the general formulae for Sloane molecules?
CnH(2n+2)
What can alkanes be described as? What does this mean?
Saturated hydrocarbons. They contain as many hydrogen atoms as possible in each molecule.
Give the properties of short chain hydrocarbons.
Boiling point: low
Volatility: easy to turn into gas
Viscosity: very runny (low)
Flammability: clean (easy)
Give the properties of long chain hydrocarbons.
Boiling point: high
Volatility: hard
Viscosity: thick (high)
Flammability: hard (smoky flame)
What is meant by boiling point?
The temperature at which the liquid boils or the gas condensed.
What is meant by volatility?
The tendency to turn into a gas.
What is meant by viscosity?
How easily it flows.
