equillibria Flashcards
what is Le Chatelier’s principle
if a reaction at equilibrium is subjected to a change in pressure, temperature or concentration, the position of equilibrium will move to counteract the change
what happens if you increase conc in reversible reaction
equillibrium will shift to try and reduce the conc (use up the increased conc)
what happens if you increase pressure in reversible reaction
equilibrium will shift to try and reduce the pressure (shifts to side with fewest number of gas particles)
what happens when you increase the temp in reversible reaction
equilibrium shifts to endothermic direction to reduce temp
conditions for making ethanol
60atm pressure
300C temperature
phosphoric acid catalyst, H3PO4
what is dynamic equilibrium
when both the rate of the forward and backward reaction are equal, the conc of reactants and products remain constant
what do catalysts do to equilibrium
they affect forward and backward reaction equally, allowing equilibrium to be reached faster
what states do we use in Kc expressions
aqueous + gases
only in homogenous equillibria
what is the one thing that affects Kc
if temperature changes
if anything else shifts equillibria the conc of reactants and products stay in same ratio
why does equillibrium shifting not affect Kc
A + B -> C + D
increasing A shifts to increase amount of C + D and decrease A + B amount
bigger number on top and bottom of Kc due to increasing A but also the equillibrium increasing C + D
why does changing the concentration of a species not affect Kc
increasing 1 species will shift equilibrium to restore the conc to be proportional so same ratio of reactants and products are still in equilibrium
how to work out Kc in opposite direction
1/ Kc for other reaction
what is the partial pressure of a gas
the pressure the gas would exert if it alone occupied the volume of the mixture
