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28 Cards in this Set

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  • Back

What is crude oil?

A mixture of hundreds of compounds, that are mainly hydrocarbons.

What are hydrocarbons?

Compounds containing only hydrogen and carbon.

What is a mixture?

A substance consisiting of two or more elements or compounds that have not been chemically combined together.

How can we separate crude oil into its different substances?

By fractional distillation.

What are most of the hydrocarbons in crude oil?


What are alkanes?

Saturated hydrocarbons.

What does saturated mean?

A hydrocarbon which contains as many hydrogen atoms as possible in their molecules.

What is the alkane general formula?


Give some examples of alkanes.

-Methane Ch4

-Ethane C2H6

-Propane C3H8

-Butane C4H10

-Heptane C5H12

-Hexane C6H14

-Heptane C7H16

-Octane C8H18

-Nonane C9H20

-Decane C10H22

Draw the formula for ethane.

Explain the process of fractional distillation.

-Crude oil is heated until it vapourises

-Passes through the fractionating column

-The gases condense when they reach the temperature of their boiling points

-They turn to liquids

-Collected at different levels

-Continuous process

What is a fractionating column?

A tall tower that is hot at the bottom and cold at the top that is used for the fractional distillation of crude oil.

What liquids are collected from the tower?

Cold Fuel Gas (below 40)

Petroleum (40-175)

Kerosene (150-240)

Diesel (220-275)

Lubricating oil (250-350)

Hot Bitumen (below 350)

What are these liquids used for?

-Fuel gas: camping gas, fuels distillation, LPG

-Petroleum: fuel for cars/motorcycles

-Kerosene: fuels jet engines, greenhouse heaters

-Diesel: fuel for lorries/trains

-Lub. oil: fuel for ships, heating large buildings

-Bitumen: roofing and road surfacing

Which chains are more useful? Why?

-Shorter chains

-Lighter fractions make better fuels

Where are the shorter chains found?

At the top of the fractionating column.

What are the properties of short chains and long chains?

Short chain Long chain

-low boiling point -high boiling point

-high volatility -low volatility

-low viscosity -viscous

-flammable -smoky flame

When fuels burn, what do they release into the atmosphere and how does this affect the environment?

-Carbon dioxide: global warming contribution

-Carbon monoxide: poisonous

-Sulphur dioxide: acid rain

-Nitrogen oxides: acid rain

-Particulates: smog/global dimming

What happens during combustion?

The carbon and hydrogen in the fuels are oxidised.

What does the combustion of hydrocarbon fuels release?


How can sulphur be removed from fuels before they are burned?

-Catalytic converter (exhaust gases react)

-Flue gas desulfurisation (react with qucklime)

What is the combustion formula?

any hydrocarbon + oxygen --> water + CO2

What is the test for water?

-Cobalt chloride paper

-Blue when dry

-Pink when water is present

How does the number of carbon atoms in a hydrocarbon affect its boiling point?

It increases the temperature of the boiling point.

What is the test for incomplete combustion?

any + oxygen --> carbon+ carbon + water

hydrocarbon monoxide

What are the advantages of using biofuels?


-Renewable and reduce greenhouse gases

-Easy to source

-Lower pollution levels

-Reduce dependency on fossil fuels

What are the disadvantages of using biofuels?

-Expensive to produce

-Fertilizers (may cause water pollution)

-Shortage of food


-Water use

How do biofuels reduce global warming (compared to fossil fuels)?

-CO2 neutral

-Reduce greenhouse gas emissions

-Stop us fro using fossil fuels