
Equilibrium constant expression for aA + bB ↔ cC + dD
 K = ^{K1}/_{K1} = [C]^{c}[D]^{d}/[A]^{a}[B]^{b}
 Product favored: K has large value
 Reactant favoried: K has a small value
 Note  Pure solids and liquids aren't included in equilibrium constant expression

Effect on equilibrium constant if equation is reversed? A coefficient is added? You add equations together?
 Reversed: K_{backward} = 1/K_{forward}
 Coefficent: K_{new} = K^{n}_{original}
 Addition: K_{new} = K_{1} x K_{2}

Relationship between K_{p} and K_{c}
 K_{P} = K_{c} x (RT)^{Δn}
 Δn = moles gas products  moles gas reactants
 note  K_{p} always given in atm

Reaction Quotient?
 same as equilibirum constant, but at ANY concentration.
 Can be compared with equilibrium constant to determine how reactants/products will change
 Q>K  [reactants] increase and [products] decrease
 Q<K  [reactants] decrease and [products] increase
 Q=K  [reactants] and [products] do not change
 If rxn has only reactants Q = 0, only products Q = ∞

Explain the simplification step and method of approximations
 Simplification: assume x is very small and eliminate x from equation (+x, x). Solve equation. If x is less than 5% of the largest initial concentration then the answer is correct.
 Method of approximations: if x is not smaller than 5% of the largest initial concentration then input the number you got into the equation. If the new answer is not less than 5% of the largest initial concentration then input the number you just got into the equation, repeat until less than 5%!

Effect of adding/removing reactants, gas volume changes, and temperature shifts
 Adding a reactant / removing a product: rxn >
 Adding a product / removing a reactant: rxn <
 When volume is reduced equilibrium favors side w/ fewer moles (gases)
 When volume is increase equilibrium favors side w/ more moles (gases)
 Temperature: determine exothermic/endothermic. Write heat into the equation (exo  heat as product, endo  heat as reactant). Consider temperature change as a change to heat within the equation. EXAMPLE  endothermic heat increases forces equilibrium >


