C8 Rates and Equailibrium Flashcards
How do you calculate the rate of a reaction using change in amount of reactants?
Rate of reaction = change in amount of reactants / time
How do you calculate the rate of a reaction using change in amount of products?
Rate of reaction = change in amount of products / time
How do you calculate the rate of a reaction using mass?
Rate of reaction = mass / time
How do you calculate the rate of a reaction using volume?
Rate of reaction = volume / time
How do you calculate the rate of a reaction using concentration?
Rate of reaction = concentration / time
When calculating with mass, why is the initial rate of reaction fast?
There are loads of reactant particles to collide with.
- rate of reaction gradually decreases as the number of reactant particles decrease over time
How does temperature affect the rate of reaction?
As temperature increases, particles contain more kinetic energy so there will be more collisions per second.
What is ‘Collision Theory’
Chemical reactions can occur ONLY when reacting particles collide with each other in:
- Correct Orientation
- Enough energy
What are factors which affect rate?
- surface area of a solid
- concentration of a solution
- pressure of a gas
- temperature of the reactants
What is activation energy?
The minimum amount of energy required for particles to react in a reaction.
Why does the increase surface are to volume ratio increase the rate of reaction?
There are more frequent collisions as there is more area for the particles to collide with.
- the SA:V is directly proportionate to the rate of reaction
Why does the increase in concentration of a solution increase the rate of reaction?
There is more of the substance for particles to collide with, meaning that the frequency of collisions increase
- the concentration is directly proportionate to the rate reaction
Why does the increase in pressure of a gas increase the rate of reaction?
The gas particles are more close together, increasing the frequency of succesful collisons.
- the pressure of gas is directly proportionate to the rate of reaction
Why does higher temperature increase the rate of reaction?
An increase in temperature, means that there is an increase in kinetic energy for the particles to collide with.
- temperature is not directly proportionate to the rate of reaction as there is an increase of energy and increase of frequent collisions
What is a closed system?
Apparatus which prevents the escape of reactants and products
What is yield?
Amount of product formed
What happens when a mixture is at dynamic equalibrium?
When the rate of forward reaction equals to rate of the reverse reaction and there is no overall change in the concentrations of reactants and products.
-* this can only occur in a closed system*
If equailibrium shifts to the right…..
….. amount of yeild (products) increases
If equalibrium moves to left….
…. amount of reactants increases
If you heat up an equalibrium…….
….. it will shift towards endothermic direction
What are examples of endothermic reactions?
- electrolysis
- thermal decomposition
- cracking
- photosynthesis
What are examples of exothermic reactions?
- combustion
- neutralisation
- displacement
- respiration
What does anhydrous mean?
A substance that dosen’t contain water
What is climate change?
the change in global weather patterns that could be caused by excess levels of greenhouse gases in the atmosphere
What is a hyrdated substance?
A substance that contain water in its crystals.
What is Le Châtelier’s Principle?
when a change in conditions is introduced to a system at equilibrium, the position of equilibrium shifts so as to cancel out the change
