5.1 Exothermic and endothermic reactions Flashcards
(10 cards)
1
Q
Conservation of energy
A
The amount of energy in the universe at the end of a chemical reaction is the same as before it took place.
2
Q
Exothermic reaction
A
A reaction that transfers energy to the surroundings so the temperature of the surroundings increases.
3
Q
Examples of exothermic reactions
A
- Combustion.
- Oxidation reactions.
- Neutralisation.
4
Q
Everyday uses of exothermic reactions.
A
- Self-heating cans.
- Hand warmers.
5
Q
Endothermic reaction
A
A reaction which takes in energy so the temperature of the surroundings decreases.
6
Q
Examples of endothermic reactions
A
- Thermal decomposition
- Reaction between citric acid and sodium hydrogen carbonate.
7
Q
Everyday use of endothermic reactions.
A
- Sport-injury pack.
8
Q
Activation energy
A
Minimum energy needed for a reaction to take place
9
Q
Equation for overall energy change
A
Overall energy change = energy taken in - energy released.
10
Q
Overall energy change and allocation to endothermic and exothermic.
A
- Endothermic = positive number.
- Exothermic = negative number.
