Topic 7(Organic Chemistry

Question 1

Hydrocarbon

Answer 1

A compound that only contains hydrogen and carbon atoms.
Properties change as the chain gets longer.

Question 2

Alkanes

Answer 2

homologous series-a group of organic compounds that react in a similar way
Saturated compounds, each carbon atoms forms four single covalent bonds.

Question 3

Methane, CH₄

Question 4

Ethane,C ₂H ₆

Question 5

Propane, C₃H₈

Question 6

Butane,C₄H₁₀

Question 7

Chains in hydrocarbons

Answer 7

Properties change as the chain gets longer.
The shorter the chain, the more volatile the hydrocarbon is and the more flammable they become.

Question 8

complete combustion

Answer 8

only occurs when there is plenty of oxygen

Question 9

Crude oil

Answer 9

Is a fossil fuel and is formed over a long period of time.
Formed by plants and animals, mainly plankton. Non-renewable.Finite source.

Question 10

Fractional distillation

Answer 10

used to separate hydrocarbon fractions.

Question 11

How does fractional distillation work

Answer 11

The oil is heated until most of it turns to a gas, then enter a fractionating column.
In this column, it is hot at the bottom and gets cooler towards the top, also known as a temperature gradient.

Question 12

What is crude oil used for

Answer 12

Provides fuel for most modern transport.

Question 13

Cracking

Answer 13

splitting up long-chain hydrocarbons.
is a thermal decomposition reaction, breaking molecules down by heating them.

Question 14

Methods of cracking

Answer 14

First one is to vaporise them, then mix with steam, and then heat them to a very high temperature. This is known as steam cracking.