Dynamic equilibrium Flashcards
What is a chemical system
the environment in which a chemical reaction occurs
What are the two types of chemical systems
Opened chemical system and closed chemical systems
What is an open chemical system
One where matter and energy is free to be exchanged between system and surroundings
What is a closed chemical system
One where matter is contained in the system so it cannot be changed with the surroundings. energy can still transfer between system and surroundings
Advantages of open chemical system
Simple to use
Easy to add reactants or remove products
Can be used to concentrate solutions
lower cost of operation
easy to monitor (visible)
Disadvantages of open chemical system
Easy to lose sample
reaction mixture can be contaminated
Reactants may need to be topped up (evaporation)
Need for fume hood
difficult to control
Examples of open chemical system
Open beaker with chemicals
Advantages of closed chemical systems
No sample loss or contamination
can be fitted with guages to monitor reaction conditions
A lot easier to control conditions
greater yield of products
Disadvantages of closed chemical systems
More complex
System has to be open to allow addition or removal of materials
higer cost of operation
difficult to view reaction progress
Example of closed chemical systems
Digestion of precious metal containing ores useing an autoclave
what is equilibrium
When the rate of the forward reaction is equivalent to the rate of the reverse reaction, chemical equilibrium has been reached.
Why is it called dynamic equilibrium
Because even though the concentrations of reactants and products remain constant, the reactions still occur.
conc of substances and equilibrium are not necessarily equal
Requirements for chemical reaction to be at equilibrium
1.Must occur in closed chemical system
2.Must be reversable (activation energy relatively low)
3.Equilibrium is dynamic
4.Rate of forward rxn equal to rate of reverse rxn
5.Concentration of each substance involved in reaction will be unchanging
What is phase equilibrium
Occurs between two states of matter
Sealed container volume of water stays same cuz rate of evaporation is equal to rate of condensation
What is solution equilibrium
The rate at which solid dissolves in a solution is equal to the rate at which it re crystalises
