Chemical Reactions: Rate of Reactions

Measure how quickly reactants are used up Measure how quickly products are formed

Rate of reaction increases when surface area is increased Greater the surface area, more particles available to react, particles collide often

Industrial processes cause fine powders to get into air Powders are highly combustible Burn readily in air due to high surface area E.g. flour in flour mills/ wood dust in saw mills Methane in coal mines can form explosive mixture with air

Catalyst can be used over and over again, not used up Catalysts provides a more ideal environment as it lowers the activation energy Often in pellets or wire gauzes - large surface for reactions to occur on

increasing concentration of reactants increases rate of reaction Concentrated solutions have more particles of solute per unit volume than dilute Higher concentration → more frequent collision of particles Rate of reaction depends on number of successful collisions per second, more collisions → faster

Higher temperature → greater rate of reaction Temperature increase, particles gain energy, move faster and collide more often Increased rate

minimum amount of energy particles need in order to react

Temperature higher → more particles have minimum activation energy when colliding, higher chance of successful reactions

chemical reactions started by ultraviolet or visible light.