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Flashcards in C1b Deck (12):
1

What are the key factors that need to be considered when choosing a fuel for a particular purpose?

Energy value - amount of energy
Availability - it is easy to get hold of
Storage - is it flammable or explosive?
Cost - good value in terms of energy content?
Toxicity - toxic? Produces poisonous fumes?
Pollution - will be adding to acid rain/ greenhouse effect
Ease of use - light easily? Move it safely?

2

Why is the amount of fossil fuels being burnt increasing?

Increasing world population.
Growth of use in developing countries like China/ India.
This means more fossil fuels ae burned to provide electricity for home use and manufacturing industries.

3

What does the combustion of a fuel release?

Useful heat energy.

4

Why does complete combustion need a plentiful supply of air?

So the elements in the fuel fully react with oxygen.

5

What does complete combustion of a hydrocarbon fuel only make?

Carbon dioxide and water.

6

Describe an experiment to show that combustion of a hydrocarbon in a plentiful supply of air produces carbon dioxide and air.

Water pump draws gases from the burning fuel through the apparatus. Water collects inside the cooled u-tube and you can show that it's water by checking it's boiling point. The limewater turns milky, showing the carbon dioxide is present.

7

Why does incomplete combustion take place?

There is a lack of oxygen.

8

Why does a blue Bunsen flame release more energy than a yellow flame?

The air hole is open, so there is more oxygen and complete combustion takes place, releasing useful energy. With a yellow flame, the air hole is closed, blocking the oxygen.

9

What does a yellow flame produce lots of?

Soot.

10

What does incomplete combustion of a hydrocarbon fuel make?

Carbon monoxide, carbon and water.

11

What is carbon monoxide?

A poisonous gas.

12

What are the advantages of complete combustion over incomplete combustion of hydrocarbon fuels?

There is more useful heat energy, no messy soot and no poisonous gases.