C5 Energy Changes Flashcards
What is the conservation of energy principle?
Energy is conserved in chemical reactions. The amount of energy in the universe at the end of a chemical reaction is the same as before the reaction takes place.
What is an exothermic reaction? Provide examples
A reaction where energy is transferred to the surroundings so that the surroundings temperature increases- combustion, oxidation reactions and neutralisation. Negative sign of energy change
What is an endothermic reaction? Provide examples
A reaction where energy is taken in from the surroundings so the surrounding temperature will decrease- thermal decomposition, reaction of citric acid and sodium hydrogen carbonate. Negative sign of energy change
What is activation energy?
Minimum amount of energy that particles need to react
What is a reaction profile?
Reaction profile is a graph which shows the relative energies of reactants and product, as well as the activation energy of the reaction
