Reversible Reactions

A reversible reaction is one where the products of the reaction can themselves react to produce the original reactants 

• If a reversible reaction takes place in a closed system, the state of equilibrium will always be reached
• The reactions are taking place in both directions but the overall effect is nil because the forward and reverse reactions cancel out
• REMEMBER: the reactions are taking place at exactly the same rate in both directions

• Equilibrium --> the amounts of reactants and products will reach a certain balance and stay there
• Closed System --> none of the reactants or products can escape

• temperature
• pressure

-all reactions are exothermic in one direction and endothermic in the other 

-if you raise the temperature, the endothermic reaction will increase to use up extra heat

-if you reduce the temperature, the exothermic reaction will increase and give out more heat

-many reactions have a greater volume on the one side, either of products or reactants

-raise the pressure --> encourage the reaction which produces less volume

-lower the pressure --> encourage the reaction which produces more volume

-DOES NOT CHANGE THE POSITION OF EQUILIBRIUM 

-catalysts speed up both the forward and reverse reactions by the same amount

-this means the reaction reaches equilibrium quicker, however you end up with the same amount of product as you would without a catalyst