Chapter 5 (Kinetics) Flashcards
What is required for a successful collision?
Particles having the activation energy.
Define activation energy
The minimum energy which particles need to collide to start a reaction.
What is the Emp?
The most probable energy
Why does the distribution curve always go through the origin?
There are no molecules with no energy.
What does the area under the curve show?
The total number of particle present.
Where is the mean energy drawn?
To the right of the peak.
Where is the Emp drawn?
At the peak of the graph.
What happens to the distribution curve as energy increases?
Curve is flatter and peak moves to the right.
What happens to the distribution curve as energy decreases?
Curve is higher and moves to the left.
Why does the curve never touch the x-axis?
There is no maximum energy for molecules.
How is a reaction able to be completed if few particles have energy greater than Ae?
Particles gain energy through collision.
Define rate of reaction
The change in concentration of a substance in Inuit of time.
(Usually measured in mol dm^-3 s^-1)
When is the rate of a reaction fastest for a change in concentration reaction?
At the start as this is when there are the most unreacted molecules.
How is rate of reaction measured in a sodium thiosulphate and hydrochloric acid reaction and why?
1 ÷ time
Approximation for the rate as it does not include concentration. Assumed that the amount of sulphur that is produced is fixed and constant.
What is the effect of increasing concentration on the rate of a reaction?
Increases as there are more particles per unit of volume and so the particles collide with a greater frequency and there will be a higher frequency of successful collisions.
