C5 - Energy Changes

Question 1

What is an exothermic reaction

Answer 1

Energy from the reacting chemicals is transferred to the surroundings, which often increase in temperature as a result. Examples include:
- Combustion.
- Neutralisation.
- Oxidation.

Question 2

What in an endothermic reaction

Answer 2

Energy from the surroundings is transferred to the reacting chemicals, causing the temperature of the surroundings to decrease. Examples include:
- Thermal decomposition.
- The reaction between citric acid and sodium hydrogen carbonate
(sodium bicarbonate)