Chemical Equilibria, Le Chatelier's and Kc (All 3)

• the forward and backward reactions proceed at equal rates • the concentrations of reactants and products are the same.

the position of the equilibrium will shift to oppose a change to it.

equilibrium shifts right to oppose increase in conc of CO yield of CO2 + H2 increases

equilibrium shifts to the left to oppose decrease in conc of CO yield of CO + H2O increases

equilibrium shifts right (fewer mole of gas) to oppose increase in pressure yield of N2O4 increases

equilibrium shifts left (more moles of gas) to oppose decrease in pressure yield of NO2 increases

decrease in volume increases the pressure increase in volume decreases the pressure

forward reaction is exothermic equilibrium will shift right to oppose decrease in temp yield of CO + H2 increases

backward reaction in endothermic equilibrium will shift left to oppose temp increase yield of CH4 + H2O increases

the rate of both forward and reverse reactions increases equally no change in position of equilibrium dynamic equilibrium is reached faster.

catalyst; does not affect the yield increases the rate of both equally less time taken to reach equilibrium pressure; higher pressure = higher yield faster rate high = more expensive temperature; lower temp = higher yield faster rate low = less expensive

Kc = [products] / [reactants]

Only TEMPERATURE

mol dm^-3

Kc expression

or re-arrange Kc expression

ICE BOX

X BOX