C7

Question 1

What is an exothermic reaction

Answer 1

One which transfers energy to the surroundings, usually by heating (rise in temp

Question 2

What is an endothermic reaction

Answer 2

One which takes in energy from the surroundings (fall in temp)

Question 3

The best example of an exothermic reaction is burning fuels - also called

Answer 3

Combustion

Question 4

Neutralisation reactions are

Answer 4

Exothermic

Question 5

Explain the uses of exothermic reactions

Answer 5

For example:

Some hand warmers use the exothermic oxidation of inon
in air (with a salt solution catalyst) to release energy.

Self heating cans of hot chocolate and coffee also rely on
exothermic reactions between chemicals in their bases.

Question 6

Fuel cells

Answer 6

Is an electrical cell that’s supplied with a fuel and oxygen and uses energy from the reaction between them to produce electrical energy efficiently

Question 7

When the fuel enters the cell

Answer 7

It becomes oxidised and sets up a potential difference within the cell