Kinetics 1 Flashcards
What must happen when two molecules collide in order for them to react
- collide with sufficient energy to cause a reaction (activation energy)
- collide in the correct orientation as some groups cause steric hindrance
How does surface area affect rate of reaction
increase in surface area
more reactant particles exposed
more frequent collisions
so increased rate of reaction
How does concentration affect rate of reaction
increased concentration
more particles per unit volume
more frequent collisions
increased rate of reaction
How does temperature affect rate of reaction
increased temperature
particles have more kinetic energy
more frequent collisions
more collisions have energy greater than activation energy
increased rate of reaction
What is on the y axis of a Maxwell Boltzmann curve
fraction of molecules
What is on the x axis of a Maxwell Boltzmann curve
energy
What does the area under the curve represent on a Maxwell Boltzmann curve
total number of molecules
How does a Maxwell Boltzmann graph change with an increase in temperature
temperature peak is lower and further to the right
the tail is higher
- particles with energy greater than activation energy is greater
How does a Maxwell Boltzmann graph change with an added catalyst
no change in shape of curve
activation energy on x axis is reduced
more particles have energy greater than the activation energy
What is the role of a catalyst
speeds up the rate of reaction by providing an alternate reaction pathway with lower activation energy
Describe the feature of an exothermic reaction profile
reactants have greater energy than products
Describe the feature of an endothermic reaction profile
reactants have less energy than the products
What is a phase
like a state but includes aqueous and liquid as seperate phases if not soluble to each other
What is a homogeneous catalyst
catalysts in the same phase as the reactants
What is a heterogenous catalyst
a catalyst in a different phase to the reactants, usually a solid
