1.5- Kinetics Flashcards
What is activation energy
The activation enery is defined as the minimum energy which particles need to collide to start a reaction
What is collision theory
Reactions can only occur when collisions take place between particles having sufficient energy the energy is usually needed to break the relevant bonds in one or either of the reactant molecules.
Explain each part of the maxwell boltzman distribution
. The area under the curve is the number of total particles that are present
. Emp is the most probable energy, this is where the peak of the graph is
. The energy distribution should go through the origin because there are no molecules with no energy
What effect does increasing temperature have on a maxwell boltzman distribution
Increasing temperatur causes the graph to shift to higher energy values, although the number of molecules with those energies decrease
How do you measure the reaction rate on a graph of concentration by time
The gradient of a graph at a certain point is the rate of reaction
What is the effect of increasing concentration and increasing pressure on the maxwell boltzman graph
. At higher concentrations and pressures there are more particles per unit volume, so the particles collide with a greater frequency and there will be a higher frequency of effective collisions
. If the concentration is also doubled then the amount of particles is also doubled
What is the effect of increasing surface area on the rate of reaction
Increasing the surface area will cause successful collisions to occur more frequently between the reactant particles and this increases the rate of the reaction
What is the effect of catalysts
Catalysts increase reaction rates without getting used up , they do this by providing an alternative route or mechanism with a lower activation energy, if the activation is lower then more particles will have energy greater than the activation energy , so there will be a higher frequency of effective collisions, the reaction will be faster
