Aromatic compounds Flashcards
The formation of crude oil
It is a mixture of hydrocarbons formed from the remains of simple marine organisms over millions of years.
The organisms died in large numbers, fell to the bottom of the ocean and were quickly buried under layers of sand and mud. Over time, these organisms decomposed under high pressure and temperature in the absence of oxygen, forming crude oil.
What is the composition of crude oils
A hydrocarbon is a molecule that contains only carbon and hydrogen atoms
Why is crude oil separated into useful products
All of the different hydrocarbons have different properties which interfere with each other.
To be used for a specific purpose, crude oil must be separated into separate products, known as fractions, using fractional distillation.
Why the different products separated from crude oil have different uses.
As the average carbon chain length of a fraction increases:
the boiling point increases
the viscosity (thickness) increases
the ease of ignition decreases
the colour becomes darker (colourless → yellow → brown)
the cleanliness of burn decreases (more soot is given off by lower fractions).
How is crude oil separated into useful products
1) The crude oil is heated until it is vaporised (boiled).
2) The gaseous crude oil enters the bottom level of a fractional distillation column, where the temperature is highest.
3) Hydrocarbons that have a boiling point higher than the temperature of the level they are on condense into a liquid and are piped away.
4) The hydrocarbons with boiling points lower than the temperature of that level remain as a gas and travel up to the next level, which is cooler.
Crude oil production and its influence politically, socially and economically
Crude oil is essential to the global economy and so countries have no choice but to pay the given amount. This means that oil-purchasing countries have less control on their own economy, which is an especially big problem for poorer countries that are still developing their industry and economy.
Any major problems in oil-producing countries (such as war, natural disasters or political upheaval) can have a major impact on the global economy.
Any country that depends on another country for its supply of crude oil can be heavily influenced by the country supplying the oil. This is because the supplier can threaten to reduce or remove the oil supply.
The crude oil industry provides a lot of jobs, which is of great help to the economy.
Burning fuels from crude oil releases carbon dioxide into the atmosphere. Higher carbon dioxide levels in the atmosphere have been linked to global warming, a major contributor to climate change.
Crude oil can leak into the environment when it being pumped from the ground or being transported around the world in ships.
