Tiêu đề EDX.Topic 12 rates of reactions .pdf ✅

Topic 13 Rates of Chemical Reactions 1
Topic 13 2 Rate of chemical reaction is a measure of how fast or slow a reaction is. Rate of reaction depends on two things And For reactants to collide successfully, they need to: This is known as collision theory. Rate = change of amount of reactant or concentration per unit time. Same reactions take few seconds while others may take thousands of years. Example: Reactions in fireworks takes a few seconds, baking takes minutes, rusting may take weeks and change of plants/fish to fossil may take thousands of years. For a reaction to happen, particles of the reactants must collide with each other with sufficient energy to react. Any factor that will increase the kinetic energy of the reacting particles or increase the frequency of collision between particles will increase the rate of reaction. How often the reactant particles are colliding How many of those collisions are successful Collide in the correct orientation Collide with enough energy (more than the activation energy). Factors Affecting Rates of Factors Affecting Rates of Reactions Temperature Pressure Catalyst Concentration Surface Area Temperature When temperature increases, the rate of reaction increases Because particles gain kinetic energy, move faster & collide more frequently per unit time. More particles will have energy greater than the activation energy so there will be more successful collisions per unit time.