Kinetics Flashcards
Collision frequency
? The number of collisions between particles per second.
Rate of reaction
? The change in concentration of a substance per unit time.
Activation energy
? The minimum energy required for the reaction to occur.
Catalyst
? provides an alternative reaction pathway with lower activation energy but remains chemically unchanged.
Heterogeneous Catalyst
? Catalyst that is in a different phase as the reactants
Homogeneous Catalyst
? Catalyst that is in the same phase as the reactants
What are the conditions for particles to react.
- Energy higher than the activation energy
- The correct orientation
Describe the maxwell boltzman distribution curve.
Image that looks like a hill
x axis - energy
y axis - Number of particles with E.
Factors affecting rate of reaction
- Concentration
- Temperature
- Pressure
- Catalyst
How does increasing the temperature affect the maxwell boltzman curve.
Flattens and shifts to the right.
Can you explain the qualitative effect of temperature changes on the rate of reaction?
Higher temperature, higher frequency of collisions, which increases the number of successful collisions. Higher temperature, more particles have energy higher than the activation energy, thus the rate of reaction increases.
Can you explain the qualitative effect of changes in concentration on the ROR.
There are more particles per unit volume, thus the frequency of collisions increases, which increases the number of successful collisions, increasing the rate of reaction.
Can you describe the qualitative effect of a change in the pressure on ROR
Higher pressure, higher frequency of collisions, higher number of successful collisions, higher ROR
Can you describe a maxwell Boltzman reaction to explain the increased rate of reaction?
The line of Ea shifts to the left, thus more particles have an energy greater than the activation energy.
What is the purpose of a catalytic converter?
Purpose - to remove pollutant gases formed in internal combustion of the engine.
Construction - finely divided powders of alloys of platinum,rhodium and palladium spread onto a ceramic honeycomb structure