Unit 2 - Topic 4 - Energy from Fuels

Question 1

What is a fuel?

Answer 1

A chemical, which burns giving out energy.

Question 2

What is combustion?

Answer 2

COMBUSTION is another name for burning. It is a reaction of a substance with oxygen, giving out energy.

Combustion of a fuel releases energy, i.e. it is an EXOTHERMIC REACTION.

Question 3

What is the unit for measuring energy?

Answer 3

The JOULE (J). The unit is named after James Prescott Joule, the physicist who did a lot research on energy.

A joule is a small quantity of energy. Often measurements of energy are given in kilojoules (kJ).

Question 4

How do you compare the quantity of energy released by different fuels?

Answer 4

The same mass of fuel must be burned in each experiment.

Question 5

How much energy is released when 1 gram of methane is burned?

Answer 5

55.7 kJ g-1

Question 6

How much energy is released when 1 gram of butane is burned?

Answer 6

49.6 kJ g-1

Question 7

How much energy is released when 1 gram of gasoline is burned?

Answer 7

48.3 kJ g-1

Question 8

How much energy is released when 1 gram of methanol is burned?

Answer 8

22.7 kJ g-1