C8 The rate and extent of chemical change

Calculating rates of reaction

Recall how each of these factors affects the rates of chemical reactions

Collision theory and activation energy

Catalysts

what is a reversible reaction?

give an example of a reversible reaction that is both exothermic and endothermic

equilibrium

what is Le Chatelier's principle?

The effect of changing concentration on equilibrium

The effect of temperature changes on equilibrium

The effect of pressure changes on equilibrium involving gases

  1. concentration of reactants
  1. pressure of reacting gases
  1. surface area of solid reactants
  1. temperature
  1. presence of a catalyst

Required practical 11: investigate how changes in concentration affect the rates of reactions

By a method involving measuring the volume of gas produced image

By a method involving a change in colour or turbidity image

calculate the mean rate of a reaction from given information about the quantity of a reactant used or the quantity of a product formed and the time taken

rate (g/s or cm3/s) = quantity of reactant/product / time

draw tangents to the curves on these graphs and use the slope of the tangent as a measure of the rate of reaction

calculate the gradient of a tangent to the curve on these
graphs as a measure of rate of reaction at a specific time

what is collision theory?

what is activation energy?

how do increases in the concentration of reactants in solution, the pressure of reacting gases, and the surface area of solid reactants, increase rate?

how does increasing the temperature increase the rate?

label the reaction profile image

what is a catalyst?

explain catalytic action in terms of
activation energy

what is meant by equilibrium in terms of chemical reactions and when is it reached?

if the equilibrium lies to the right, what does this mean?

if the equilibrium lies to the left, what does this mean?

how does increasing the concentration of reactants affect the concentration of products?

how does decreasing the concentration of products affect the concentration of reactants?

increasing temperature

decreasing temperature

how are products affected for an endothermic reaction? eg N2+ 3H2 >/< 2NH3

how are products affected for an exothermic reaction? eg N2+ 3H2 >/< 2NH3

how are products affected for an endothermic reaction? eg N2+ 3H2 >/< 2NH3

how are products affected for an exothermic reaction? eg N2+ 3H2 >/< 2NH3

how does an increase in pressure affect equilibrium? eg N2+ 3H2 >/< 2NH3

how does an decrease in pressure affect equilibrium? eg N2+ 3H2 >/< 2NH3