Kinetics (Physical) Flashcards
activation energy
the minimum amount of energy for particles to collide with for a successful reaction to take place
catalyst
a substance that increases the rate of a reaction without being changed in chemical composition or amount. they work by providing an alternative reaction pathway with a lower activation energy
collision theory
reactions can only occur when collisions take place between particles having sufficient energy
effect of concentration on reaction rate
as the concentration of reactant increases, reacting particles get closer together meaning they will collide more often. as a result, there will be a higher rate of successful collisions and a faster rate of reaction
effect of pressure on reaction rate
as the pressure of gaseous reactants increases,reacting particles get closer together meaning they will collide more often. as a result, there will be a higher rate of successful collisions and a faster rate of reaction
effect of temperature on reaction rate
increasing the temperature means the particles will have more kinetic energy and so will move faster. if the molecules are moving faster they will collide more often and, since they’ve gained kinetic energy, a larger proportion of the particles will have at least the activation energy. for both these reasons the rate of reaction increases.
Maxwell-boltzmann distribution
shows the distribution of the molecular energies in a gas at a constant temperature. the area under the curve indicates the total number of particles present
rate of reaction
the measure of the amount of product formed or reactant used over time. the units of rate of reaction may be given as g/s, cm³/s, or mol/s