General Chemistry - Equilibrium

MCAT Chapter 6

irreversible reactions

reaction proceeds in one directly only

Reversible reaction

those in which reaction can proceed forward or reverse

dynamic equilibrium

Forward and reverse reactions are occuring

Static equilibrium

reactions stopped

entropy

nmeasure of distribution of energy throughout a system or between a sytem and its environment

law of mass action

if system is at equilibrium at a constant temp, then the following ratio is constant

What does Q < Keq mean

forward reaction has not yet reached equilibrium, there is a greater concentnration of reactants than at equilibrium and the forward rate of a reaction is increased to restore equilibrium

What does Q=Keq mean

reaction is in dynmaic equilibrium, the reactants and products are present in equilibrium proportions, the forward and reverse rates of reaction are equal

What does Q>Keq mean

forward reaction has exceeded equilibrium, there is a greater concentration of products than at equilibrium, the reverse rate of reaction is increased to restore equilibrium

Q<Keq, delta G< O

reaciton proceeds in forward direction

Q=Keq delta G = 0

reaction is in dynamic equilibrium

Q>Keq and delta G > 0

reaction proceeds in reverse

Le Chatlier’s Principle

If stress is applied to a system the system shifts to relive that applied stress

What happens if reactants are added or products are removed

Q<Keq and reaction will react in forward direction until Q=K

What happens in reactants are removed or products are added

Q>K and reaction will spontaneously react in the reverse direction till Q=K