Energy Changes Flashcards
what is an exothermic reaction
a reaction that transfers energy to the surroundings, that gives out heat
what is activation energy
minimum amount of energy needed to start a reaction
how can you tell a graph shows an exothermic reaction
the energy of the products is lower than the energy of the reactants so energy is released to surroundings
examples of exothermic reactions
combustion
neutralisation
oxidation
what is an endothermic reaction
a reaction that takes in energy from the surroundings, it takes in heat (gets colder)
how can you tell a graph shows an endothermic reaction
the energy of the reactants is lower than the energy of the products so energy is taken into the reaction from the surroundings
examples of endothermic reactions
thermal decomposition of calcium carbonate
photosynthesis
sports injury pack
bond energy calculation method
1- highlight bonds broken and bonds made
2- work out the energy for bonds broken
3- work out energy for bonds made
4- work out enthalpy change for reaction
how do you calculate enthalpy change
bonds broken - bonds made
