C5 - Energy Changes Flashcards
Exothermic and endothermic reactions, bond energies, cells and batteries, fuel cells
1
Q
Exothermic and Endothermic Reactions -
What is an exothermic reaction?
A
transfers energy to surroundings (usually by heat) - shown by a rise in temperature
2
Q
Exothermic and Endothermic Reactions -
What is an example of an exothermic reaction?
A
- Combustion - burning fuels (gives out a lot of energy)
- Neutralisation (acid+alkali)
-many Oxidation reactions (eg sodium + water)
3
Q
Exothermic and Endothermic Reactions -
What are the every day uses of exothermic reactions?
A
- hand warmers (oxidation of iron in air with a salt solution catalyst)
- self heating cans (hot chocolate and coffee rely on chemical reactions between chemicals in their bases)
4
Q
Exothermic and Endothermic Reactions -
What is an endothermic reaction?
A
Takes in energy from surroundings (shown by fall in temperature)
5
Q
Exothermic and Endothermic Reactions -
Which reaction is more common?
A
Exothermic
6
Q
A
