Kinetics model answers Flashcards
Define rate of reaction
Change in concentration per unit time
Define activation energy
Minimum energy needed for reaction to occur OR for successful collisions
What is the effect of an increase in temperature on the rate of a reaction? Explain with reference to Maxwell-Boltzmann distribution
Increases
At higher temperature, the area under the curves at E>Ea increases as MORE MOLECULES/PARTICLES have activation energy/minimum energy needed to react
What is the effect of catalyst on rate of chemical reaction? Explain with reference to Maxwell-Boltzmann distribution curve.
Increases
Catalyst provides alternative route
With lower activation energy
So that more successful collisions between molecules per second/more molecules able to react
Define catalyst
Speeds up reaction rate
Without being chemically changed/used up
How does catalyst work?
Provides alternative reaction route
With a lower activation energy
In terms of behaviour of particles, explain why rate of reaction decreases with time
Fewer collisions
One reactant/ reactants used up
Axis of Maxwell-Boltzmann distribution
x-axis: energy
y-axis: number of molecules
two requirements for reactions to occur between molecules in the gas phase
Collisions
With sufficient energy
Why does temperature have greater effect on initial rate of reaction than concentration?
For small increase in temperature, more molecules have energy greater than activation energy
Why is a reaction slower at lower temperature?
Fewer molecules have energy greater than activation energy/sufficient energy
How does equations suggest that a substance is behaving like a catalyst?
Remains unchanged/not used up in overall equation
Offers alternative reaction route/acts as intermediate
explain the origin of E-Z isomerism
Limited rotation around C=C bond
2 different atoms/groups on each of the C atoms in the C=C
