Reaction profiles Flashcards
What do reaction profiles show?
The relative amounts of energy contained in the reactants and products in a reaction, and how the energy changes over the course of the reaction
What is energy in reactants/products measured in?
Kj/mol kilojoules per mole
How are reaction profiles drawn?
A curved line, from the reactants to products
What does the peak of the curve In a reaction profile show?
The energy input required for the reaction to take place. The activation energy
What does an exothermic reaction profile look like?
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What does the reaction profile of an endothermic reaction look like?
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What does the difference in energy between the reactants energy and products energy show?
The amount of energy released/absorbed from the environment; the energy change during the reaction, measured in KJ/mol
What is the activation energy?
The minimum amount of energy needed before colliding particles of reactants (have enough energy to) cause a reaction
Where is the activation energy seen on a reaction profile?
Between the energy level of the reactants and top of the curve
Is bond breaking or bond making exothermic?
Bond making
Why is bond making exothermic?
Because the particles need to loose energy so they can come together (energy is no longer overcoming forces) and form a bond
Why is bond breaking endothermic?
Because particles need to be given energy until they have enough to escape the forces holding them together (to break the bond)
What happens if colliding particles of reactants collide with less energy than the activation energy?
They just bounce off eachother
Why are endothermic reactions endothermic?
The energy released when new bonds are formed is greater than the energy put in to break the original bonds
