sbc 200 Lecture Notes - Lecture 8: Reaction Rate, Reaction Mechanism, Dd National
Document Summary
Particles must collide in order to react. The higher the concentration of reactants, the greater the reaction rate. A higher concentration of reactant particles allows a greater number of collisions. The physical state of the reactants influences reaction rate. Substances must mix in order for particles to collide. The higher the temperature, the greater the reaction rate. At higher temperatures particles have more energy and therefore collide more often and more effectively. Reaction rate is measured in terms of the changes in concentrations of reactants or products per unit time. Rate = change in concentration of a/ change in time = -( conc a2 - conc a1/ t2 - t1) The negative sign is used because the concentration of a is decreasing. A reaction has an individual order with respect to each reactant. If the rate doubles when [a] doubles, the rate depends on [a]1 and the reaction is first order with respect to a.