Rate of reaction - the speed in which reactants turn into products
Mean rate of reaction = quantity of products used dived by time taken
Mean rate of reaction = quantity of reactants used dived by time taken
Factors that affect rate of reaction
temperature - when increased particles collide more frequently
concentration/pressure - when increased there will be more particles per unit of volume resulting in more collisions
Factors that affect rate of reaction
surface area - a higher surface area will cauae more collisions
catalyst - speeds up rate of reaction and lowers activation energy
Reversible reactions - the products can react to form the original reactants
The direction of reversible reactions can be changed by changing the conditions.
If a reversible reactions is exothermic in one direction, it is endothermic in the other
Equilibrium is reached when forward and reverse reactions occur at exactly the same rate
La chateliers principle - if you change the conditions of a reversible reaction the position of equilibrium will shift and counteract this change
Collision theory - chemical reactions can occur only when reacting particles collide with each other, and with sufficient energy
The minimum amount of energy that particles must have to react is called activation energy
Catalyst – increased the rate of reaction without being used up in the reaction.
The effects of changing concentration
If the concentration of a reactant is increased, more products will be formed until equilibrium is reached again, the concentration of the product is decreased more reactants will react until equilibrium is reached again
if the temperature of a system are equilibrium is increased
The amount of products at equilibrium increases for Endo reaction
The amount of products are equilibrium decreases for an Exo reaction
If the temperature of a system at equilibrium is decreased
The amount of products are equilibrium decreases for an Endo reaction
Amount of products at equilibrium increases for an Exo reaction
effects of pressure changes on equilibrium
An increase in pressure causes the equilibrium to shift towards the smaller number of molecules
A decrease in pressure causes the equilibrium to shift with the larger number of molecules
