Key words

• Activation Energy = Ea = minimum amount of energy that particles must collide with to react
• Catalyst = Increases rate --> provides a different reaction pathway with a lower Ea (not used up)
• Effect of conc = increasing concentration of reactants = reacting particles will be closer together --> will collide more often = higher rate of successful collisions at a faster rate
• Effect of pressure = Increases pressure of gaseous reactants = particles are closer together --> collide more often = higher rate of successful collisions at a faster rate
• Effect of surface area = increasing surface area of reactants --> more exposed reacting particles --> more frequent successful collisions so faster rate
• Effect of temp = increasing temp means particles will have more kinetic energy --> move faster --> collide faster + more often + more particles have Ea --> more successful collisions so rate of reaction increases
• Enzymes = biological catalysts which speed up biochemical reactions by reducing the Ea by giving the reaction a different path to follow (therefore easier for particles to reach Ea)
• Precipitation reaction = solutions react to form a precipitate (insoluble product)