Rates of Reaction and Equilibrium Flashcards
What affects the Rate of Reaction?
- Temperature
- Pressure in gases / concentration in liquids
- Surface Area
- Catalyst (presence of a catalyst)
How does increasing the temperature affect the rate of reaction?
It increases the kinetic energy, so there is a higher frequency of successful collisions, thus meaning that the rate of reaction increases.
How does decreasing the temperature affect the rate of reaction?
It decreases the kinetic energy, which lowers the frequency of successful collisions and thus lowers the rate of reaction.
How does increasing the concentration affect the rate of reaction?
This increases the number of particles which increases the number and frequency of successful collisions, thus increasing the rate of reaction
How does decreasing the concentration affect the rate of reaction?
It decreases the number of particles which decreases the number and frequency of successful collisions, thus decreasing the rate of reaction overall
How does increasing the surface area affect the rate of reaction?
It is because it increases the frequency of collisions.
- smaller size = larger surface area
This increases the rate of reaction
How does the presence of a catalyst affect the rate of reaction?
It lowers the activation energy (uses an alternative pathway), so the frequency of successful collisions increases and so does the overall rate of reaction
What is activation energy and what is it’s symbol?
The minimum energy needed for a collision to occur.
Ea
What is Dynamic Equilibrium?
It is a situation in which the composition of a constant concentration reaction mixture does not change because both forward and back wars reactions are proceeding at the same rate.
It occurs in a closed system.
What is a closed system?
One where no chemicals can get in or out of a system
What is a homogenous reaction?
All reactants and products are in the same state e.g.
- N2(g) + 3H2 (g) —> 2NH3 (g
the arrow is reversible)
What is a heterogeneous reaction?
Reactants and products are in different states.
What is Le Chatelier’s principle?
If any factor is changed which affects an equilibrium, the position of equilibrium will shift so as to oppose the change
