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Flashcards in Crude Oils And Fuels Deck (19)
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What is crude oil?

A mixture of different compounds which are not chemically joined together. These compounds are called hydrocarbons

1

What are hydrocarbons?

Compounds of hydrogen and carbon covalently joined together

2

What are alkanes of of these hyrocarbons?

Bonded structures of hydrogen and carbon which are saturated

3

What does saturated mean?

They have single bonds

4

First three alkanes

Methane, ethane and propane

5

What is the chemical structure of ethane?

H H
| |
H - C - C - H
| |
H H.

6

What is the formula for alkanes?

CnH2n + 2

7

What is special about alkanes of hydrocarbons?

They are unsaturated.

8

What does unsaturated mean?

They have a double bond

9

What does saturated mean?

No more hydrogens can be added

10

How do we separate these hydrocarbons?

As they are a mixture, by boiling points via fractional distillation

11

Why do hydrocarbons with smaller molecules make better fuels?

- more volatile (turn to gas easily)
- less vicious (flow easily)
- more ignited
- burn cleaner

12

What do fuels do?

Store energy which it releases when burnt

13

What do fuels need to burn?

Oxygen and some sort of ignition

14

When hydrocarbons are burnt what happens?

The hydrogen is oxidised (gains oxygen) to water
If complete combustion carbon is oxidised into carbon dioxide

15

What happens in incomplete combustion of hydrocarbons?

Lack of air so hydrogen is still oxidised but instead of carbon dioxide we get carbon monoxide

16

Problems with carbon monoxide?

Toxic gas
Sticks to haemoglobin in red blood cells lowers their capacity
Particles of carbon also released causing asthma

17

What is the problem with burning fuels?

We also burn impurities which cause problems for the environment

18

What Impurities in fuels do we burn?

Sulfur impurities which react with oxygen to produce sulfur dioxide which causes acid rain

Carbon monoxide produced from incomplete combustion in cars

Nitrogen oxide also produced which is a toxic gas