dynamic equilibrium means the rate of the forward reaction is equal to the rate of the reverse reaction; the reactions haven't stopped

static equillibrium means the reactions have stopped

aA + bB ↔ cC + dD

K_eq = ([C]^c[D]^d)/([A]^a[B]^b)

if a system is at equilibrium at a constant temperature the above ratio is constant, this defines the position of equilibrium; solids and liquids do not appear in the law of mass action, only gaseous and aqueous species

Q = ([C]^c[D]^d)/([A]^a[B]^b)

relates the reactant and product concentrations at any given time during a reaction

• if Q < K, ΔG < 0, an dthe reaction proceeds in the forward direction
• If Q = K_eq, ΔG = 0, and the reaction is in dynamic equilibrium
• If Q > K_eq, ΔG > 0, and the reactions proceeds in the reverse direction 

when a chemical system experiences a stress, it will react so as to restore equilibrium

• Increasing reactants/decreasing products shift right, decreasing reactants/increasing products shifts left
• Gaseous system - Increasing pressure(decreasing volume) shifts towards fewer moles of gas, Decreasing pressure(increasing volume) shift towards more moles of gas
• Temperature changes actually change the equilibrium constant - Increasing temp of endothermic/decreasing temp of exothermic shifts right, Decreasing temp of endothermic/increasing temp of exothermic shifts left