Topic 16 - Kinetics 2 Flashcards
Two ways the rate determining step can be found?
Look for the slowest step in a reaction.
Look for the step that contains both species in the rate equations as reactants.
What does a zero order reaction for concentration against time look like?
Straight line with a negative gradient
What is the rate determining step?
The slowest step in a reaction
What pathway do tertiary halogenoalkanes undergo in nucleophilic substitution?
SN1 pathway
What pathway do primary halogenoalkanes undergo in nucleophilic substitution?
SN2 pathway
How many steps are involved in a SN2 mechanism and how many molecules are required?
1 step
2 molecules required
How many steps are involved in a SN1 mechanism and how many molecules are required?
2 steps
1 molecule required
What is the transition state in the SN2 pathway?
Where both carbon halogen bond and carbon hydroxyl bond are attached at the same time.
Why can’t tertiary halogenoalkanes react in the SN2 pathway?
Steric Hinderance - OH group is blocked by 3 carbon groups.
What happens to an acidic mixture when sodium hydrogencarbonate is added?
Stops reaction
By neutralising acid
What is a heterogeneous catalyst?
A catalyst that is in a different physical state to reactants.
What is a homogeneous catalyst?
A catalyst that is in the same physical state to reactants.
What is autocatalysis?
Where a product of a reaction also functions as a catalyst.
What is the continuous method when determining the order of a reaction?
Taking a sample of mixture and half life is determined.
What is the initial rates method when determining the order of a reaction?
Measure initial rate, plot a rate against concentration graph.
Use shape to determine what order
