Reaction Kinetics Flashcards
Activation energy
The minimum amount of energy which the reactant particles must possess to overcome the energy barrier in order for effective collisions to result in a chemical reaction.
Catalyst
A substance that increases the rate of reaction by providing an alternative pathway with lower activation energy. It remains chemically unchanged at the end of a reaction.
Rate equation/ rate law
The rate equation relates the rate of reaction to the concentration of the reactants raised to the appropriate powers.
Order of reaction
The power to which the concentration of a reactant is raised to in the rate equation.
Rate constant
A proportionality constant in the rate equation that relates the concentrations of the reactants to the rate of reaction.
(k is temperature and catalyst dependent)
Half-life
Time taken for the concentration of a reactant to decrease to half of its original value.
Enzymes
Biological catalysts that speed up or alter the rate of reactions in living systems while remaining chemically unchanged at the end of the reaction.
Requirements for an effective collision
Particles collide with a minimum amount of energy (activation energy)
Particles collide in the correct orientation that can lead to the rearrangement of the atoms
Factors affecting rate of reaction (Think to yourself HOW they do so)
- Temperature
- Concentration (No. of reactant particles per unit volume increases)
- Catalyst
- Physical state
- Light
How temp affect RoR
1) At higher temperature, total number of reactant particles remain unchanged but the average kinetic energy of the reactant particles increases
2) The number of reactant particles with energy greater than the activation energy increases.
3) Frequency of effective collisions in the reaction increases
4) Since rate of reaction is proportional to 3), it increases.
