SQA National 5 Chemistry Endothermic & Exothermic
This page covers the following topics:
1. Loss of energy
2. Energy change of reactions
3. Determining energy changes
Energy is conserved in reactions, meaning it is never created or destroyed but rather transferred to or from a reaction environment. Energy is gained and lost from a reaction mixture as bonds are broken or made.
If a reaction gives out heat it is exothermic and if it draws in heat it is endothermic.
Experimentally you can determine if a reaction is endothermic or exothermic by checking for energy given out or taken in. Simply this can be done by feeling the reaction container or using a thermometer for heat change, and observing any light energy given out.
In the reaction between citric acid and sodium hydrogencarbonate the energy of the surroundings drops by 4 degrees celcius, is this exothermic or endothermic?
Does the reaction profile diagram shown show an endothermic or exothermic reaction?
Oxidation reactions, including combustion, usually heat up their surroundings are they endothermic or exothermic?
When hydrochloric acid is neutralised with sodium hydroxide in a polystyrene cup you can feel the temperature of the cup increase, is this endothermic or exothermic?
Suggest in what form energy may be lost from a reaction mixture?
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