Exothermic And Endothermic Reactions Flashcards
What is an exothermic reaction
A reaction that transfers energy to the surroundings
What is an endothermic reaction
A reaction that takes in hear from the surroundings
An example of an exothermic and endothermic reaction
Hydrochloric acid & magnesium
Hand warmers
(exothermic)
Water and sodium thiosulfate
Cool packs
(endothermic)
What is activation energy
Minimum amount of energy the reactant particles need in order to collide and react
How can you tell on a graph when a reaction is exothermic
When the energy change is negative as energy is lost to the surroundings
How can you tell on a graph when a reaction is endothermic
When the energy change is positive as energy gained from the surroundings
What is bond energy
Energy needed to break a bond
How to work out the bond energy
Total energy needed - the total energy released
(If the value is negative it’s exothermic and if it’s positive it’s endothermic)
