La Chatelier And Dynamic Equilibria Flashcards
Give a definition for equilibrium. A formal one.
Equilibrium is the point where the rates of the forwards and backwards reactions are the same. As a result the concentration of particles and reactants remain constant.
What is La Chatelier’s principle?
It’s the idea that if you make a change to the conditions of a reversible reaction, the reaction system and equilibrium will move to oppose said change
How is La Chatelier’s principle useful to us?
We can use it to predict effect of changes made to reaction systems
What are the factors affecting equilibrium
Temperature
Gas pressure
Concentration of reactants and products
How is gas pressure caused?
It’s caused by gas particles hitting the wall of the container they’re in. So the higher the concentration of gas particles, the higher the pressure
Why does pressure only affect gas?
Because particles in a gas are further apart. And it only affects gases in EQUILIBRIUM
How do we use a symbol equation to determine gas pressure on each side?
We look at the big number attracted to the symbol. It tells us how many gas molecules are on each side and consequently which side will have a higher gas pressure
If there are more gas molecules on the left side of the reaction what does this mean for the pressure.
There will be higher gas pressure on the left hand side, and lower gas pressure on the right hand side
What happens if there are more molecules of gas on the right side of the reaction
Right side will have higher pressure and left side will give lower pressure
If you increase the gas pressure and there are more molecules on the left side what will happen?
If you increase gas pressure, then according to La Chatelier the reaction system will move to oppose the change. It can do this by decreasing the pressure. To decrease the pressure, position of equilibrium must shift to the side with fewer gas molecules (the right in this case): this also means more products are made
If you decrease the pressure of a reaction and there are fewer molecules on the right side, what will happen
If you decrease the pressure, reaction system moves to oppose the change by increasing the pressure. To increase pressure, equilibrium position must shift to the side with more gas molecules (the left). Less products will be made though
What happens if you increase the pressure to a reaction with the same amount/moles of gas molecules on each side?
If both sides have the same amount of gas molecules (and therefore same gas pressure to them) then either increasing or decreasing the pressure would have no effect because there is nothing the reaction can do to oppose the change so conc. of products and reactants remain the same and so does equilibrium
