S4 - Energy level diagrams Flashcards
What do energy level diagrams show?
How the energy levels of the reactants change when they react to form the products (shows if its exothermic or endothermic)
What do exothermic reactions look like on an energy level diagram?
The products are at a lower energy than the reactants
What does the difference in height bwteen the reactants and products represent?
The energy given out in the reaction (per mole) - the enthalpy change is -ve
What does the initial rise in the line represent?
The energy needed to break the old bonds (activation energy)
What do endothermic reactions looks like on energy level diagrams?
The products are at a higher energy than the reactants, so thr enthalpy change is +ve
What is activation energy?
The minimum energy needed by reacting particles for the reaction to occur
What does a catalyst do in reactions?
Makes them faster by providing an alternative reaction pathway with a lower activation energy
What curve represents the activation energy on this graph?
The lower curve as it shows the less initial energy needed for the reaction to begin
What remains the same in the reaction with a catalyst?
The overall energy change - catalysts are not used up during reactions
