Kinetics + Maxwell-Boltzmann

• Particles in a liquid/solution/gas have a range of kinetic energies
• The range of kinetic energies of particles in a gas is represented by the Maxwell-Boltzmann distribution
• A Maxwell-Boltzmann graph must start at the origin since no particles can have no energy
• The peak of the curve of a Maxwell-Boltzmann graph shows the most probable value for the energy of the particles
• The are under a Maxwell-Boltzmann curve represents the total number of particles
• The area under a Maxwell-Boltzmann curve, to the right hand side of the activation energy, represents the particles with enough energy to react
• The line of a Maxwell-Boltzmann graph levels out, but never touches the x axis
• For a successful collision, particles have to collide in the correct orientation and with the correct amount of energy
• Activation energy is the minimum energy needed for a reaction to occur
• The rate of reaction is the rate of change in concentration per unit of time
• As temperature increases, rate of reaction increases because the proportion of particles with the activation energy increases, and collisions are more frequent
• A higher temperature results in a Maxwell-Boltzmann distribution curve that has a peak further to the right and is broader
• An increase in concentration (or pressure in gases) increases the rate of reaction because there are more particles per unit volume, so there are more collisions
• An increase in concentration (or pressure in gases) results in a Maxwell-Boltzmann distribution curve that is a similar shape, but shifted upwards
• When concentration doubles, rate of reaction doubles
• A catalyst is a substance that increases the rate of reaction but is not used up or changed
• Catalysts work by providing an alternative reaction pathway that has a lower activation energy
• Catalysts increase the rate of reaction because the activation energy decreases so more particles have an energy greater than the activation energy
• Catalysts don't change the curve of a Maxwell-Boltzmann graph, but instead decrease where the activation energy line is drawn
• Activation energy is measured in Joules (J)
• The movement of particles in a given system is random
• A Maxwell-Boltzmann curve starts at the origin because particles cannot have no energy
• Maxwell-Boltzmann distributions can show molecular energies or particle energies
• Individual particles can slow down or speed up because they sometimes lose or gain kinetic energy in unsuccessful collisions
• the most probable energy is not the same as the mean energy
• The mean energy is to the right of the most probable energy