Topic 15 Kinetics 2 Flashcards
(21 cards)
What are the units for the rate constant(K) when the overall reaction is 2
Mol^-1 dm^3 s^-1
What are the units of rate constant when order of reaction is 1
S^-1
What are the units of rate constant(K) when the overall order is 3
Mol^-2 dm^6 s^-1
Rate of reaction definition?
The change in the concentration or amount of reactant used up or product produced in a given time
What does the rate equation link?
The rate equation links rate with concentrations of substances.
What is the rate constant represented by?
The rate constant is represented by ‘k’.
What does a larger value of ‘k’ indicate?
The larger the value of ‘k’, the faster the rate of reaction.
When is the rate constant fixed?
The rate constant is only fixed at a particular temperature.
What happens to the rate constant when temperature changes?
If the temperature changes, so does the rate constant.
What happens to ‘k’ when temperature increases?
‘k’ increases when temperature increases.
How does increasing temperature affect particle collisions?
As we increase the temperature, the particles have more kinetic energy and they collide more often.
What is the general form of the rate equation?
Rate = k [A]^a [B]^b
But the concentrations of the substances remain constant.
What characterizes a zero order reaction?
The rate is constant and represented by a straight line graph. Changing concentration doesn’t change the rate.
Half-life decreases.
What characterizes a first order reaction?
The rate changes in equal amounts and is represented by a shallow curve graph. Changing concentration changes the rate equally.
Half-life is constant.
What characterizes a second order reaction?
The rate changes in unequal amounts and is represented by a steep curve graph. Changing concentration changes the rate squared.
Half-life increases.
What are the two types of nucleophilic substitution mechanisms for halogenoalkanes?
The two types are SN1 and SN2 mechanisms.
What is characteristic of SN1 reactions?
SN1 reactions have only 1 molecule or ion in the rate determining step.
What type of halogenoalkanes react via an SN2 mechanism?
Primary halogenoalkanes react via an SN2 mechanism.
What is characteristic of SN2 reactions?
SN2 reactions have 2 molecules or ions in the rate determining step.
What type of halogenoalkanes react via SN1 and SN2 mechanisms?
Secondary halogenoalkanes react via SN1 and SN2 mechanisms.
What type of halogenoalkanes react via an SN1 mechanism?
Tertiary halogenoalkanes react via an SN1 mechanism.
