What is Crude oil
a thick black liquid made up of a mixture of hydrocarbons and has high viscosity
How is crude oil made
It is formed from the remains of ancient biomass - living organisms (mostly plankton) that died many millions of years ago. Under conditions of high temp and high pressure with the absence of oxygen and has high viscosity.
What is combustion
Hydrocarbons are used as fuels. This is because when they react with oxygen they release a lot of energy. This reaction is called combustion. Complete combustion is a type of combustion where the only products are carbon dioxide and water. And a good supply of o2
What is incomplete combustion
Incomplete combustion is a limited supply of O2 produces Co+H2O
Or C(s)=soot
Is combustion a oxidation reaction?
Combustion is a oxidation reaction because it releases oxygen from fuels (alkanes,hydrocarbons)
What is the combustion chemical equation
CH4+2O2-)Co2+2H2O
(Endo). (Exo)
H
H-C--H
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HHow are combustion reactions related to endo and exothermic reaction
Combustion reactions are exothermic. reactions in which the fuel combines with oxygen, releasing energy.
Viscosity
How much a substance resits flowing
How does endothermic link to combustion
If energy is absorbed by a reaction, the reaction is endothermic. When petrol burns via a combustion reaction, the energy released can be used to power a car.
Whats volatility
Volatility describes how easily a substance will vaporize (turn into a gas or vapor).
Why do Long chain have low flammability
As the chains get longer, the intermolecular forces between them increase in strength. As such, more energy is required to overcome these forces
Why do short chain have high flammability
Shorter hydrocarbon molecules have weaker intermolecular forces and lower boiling points. They are highly volatile and therefore extremely flammable.
Why do short chain have low boiling point chemitry
As we decrease surface area, we are going to decrease intermolecular Van Der Waals interaction
Why do long chain have high boiling point chemitry
Longer hydrocarbon molecules have a stronger intermolecular force. More energy is needed to move them apart so they have higher boiling points
Why do long hydrocarbons have high viscosity
They get tangled up with each other
Why do short chain have a lower viscosity
They do not get tangled up within themselvs
How are different hydrocarbons in crude oil separated?
into fractions based on their boiling points in a process called fractional distillation.
All the molecules in a fraction have a similar number of carbon atoms, and so a similar boiling point.
The process takes place in a fractionating column, which is hot at the bottom and cooler at the top.
What is the process for fractional distillation
1 crude oil is vapourised (turned into a gas by heating)
2 the hydrocarbon gases enter the column
3 the hydrocarbon gases rise up the column
4 as hydrocarbon gases rise up the column they cool down
5 when the different hydrocarbons reach their boiling point in the column they condense
6 the hydrocarbon fraction is collected.
What are alkanes
Hydrocarbons that only have single bonds
What are the first four alkanes
Methane,ethane,propane,butane
What is the general formula for the alkanes?
CH2n +2
What is a hydrocarbon?
Compounds containing Hydrogen and Carbon only
Two examples of intermolecular structures
Poly(ethane) and water
Why is crude oil not a formulation?
It is a mixture of many different hydrocarbons.
It is not designed for a specific purpose.
