Curriculum Outcomes (1) Understand the importance of energy in gas and liquid collisions: the Maxwell Boltzmann distribution and activation energy. понимание значимости энергии при столкновении частиц в газе и жидкости: распределение Максвелла-Больцмана и энергия активации
Curriculum Outcome (2) Use these concepts to give a comprehensive account of the effects of temperature and concentration on the rate of a reaction применение данных понятий для объяснения влияния температуры и концентрации на скорость реакции
Curriculum Outcomes (3) Know the meaning and definition of catalyst изучение значения и определения термина «катализ»
Curriculum Outcome (4) Understand the process of catalysis and how catalysis works понимание процесса катализа и способа его действия
Kinetic Energy of Particles All particles that make matter are constantly moving or vibrating. Adding heat to matter causes these particles to have increased kinetic energy. The particles move faster… … on average
Kinetic Energy is Variable In any sample of matter, the kinetic energy of the particles present shows variation. The variation is described by the Maxwell-Boltzmann Distribution
Maxwell-Boltzmann Distribution As the temperature increases, the median particle speed / energy also increases.
Collisions Chemical reactions occur when suitable chemical species collide. Collisions only result in a reaction if the particles collide with enough energy to get the reaction started.
Activation Energy The minimum energy required is called the activation energy for the reaction. Only a fraction of the total population of a chemical species will be able to collide with enough energy to react (E E a )
Effect of Temperature Increasing the temperature increases the number of particles with sufficient activation energy for reaction
Catalysts and Activation Energy To increase the rate of a reaction you need to increase the proportion of successful collisions. Catalysts increase the rate of reaction by providing an alternative way for the reaction to happen which has a lower activation energy. A catalyst lowers the activation energy but remains unchanged and unused by the reaction.
Concentration and Rate of Reaction Increasing the concentration of reactants increases the number of collisions that result in a chemical reaction. Increasing the pressure of gases has the same effect.
Surface Area If particles are gaseous or liquid they can mix easily and increase the chance of collisions occurring. For solids, increasing the surface area by using powders rather than large solids allows reactants to mix more freely.