Chemical Equilibrium and Reaction Rates

Equilibrium Rate

Rate of forward and reverse reactions equal. (the amount IS NOT necessarily equal)

Equilibrium Constant (K)

Fixed value at constant temperature for reactions.

-does not include solids or pure liquids. Only includes aqueous or gasseous

Rate Constant (k)

Proportionality factor in rate equations.

Partial Pressure

Pressure exerted by a single gas component.

ICE Tables

Initial, Change, Equilibrium

-how much is there to begin, what changes, E amount at equilibrium

Common Ion Effect

Decrease in solubility due to common ions.

Solubility Product (Ksp)

Product of ion concentrations at saturation.

what is ∆n

mols of gasseous product - reactants in reaction

-if ∆n = 0. Kp = Kc

-if ∆n does not = 0. Kc != Kp

How does K change when EQ changes?

if adding EQ's - multiply K values

if doubling EQ - K^2

if flipping EQ - reciprocal of K

if diving by 2 - square root

Qp

pp(product)/pp(reactant)

-constant at any state in the reaction.

-essentially you can put any values in and it will give you a constant, but this is not the equilibrium constant

-if Kp=Qp then the reaction is at equilibrium

Dynamic Equilibrium

Continuous process where rates of reactions equal.

Le Chatelier's Principle

System shifts to counteract changes in equilibrium.

-can use Q by comparing to the K value from there

Le chatelier with a smaller container

pressure increases, so overall, the pressure must decrease

-ess use the Q and the degree to determine what needs to change

Reaction Stoichiometry

Relationship between reactants and products in reactions.

Aqueous Solutions (aq)

Solutions where water is the solvent.

Gas Phase (g)

State of matter where substances are gaseous.

Solid Phase (s)

State of matter where substances are solid.

Liquid Phase (l)

State of matter where substances are liquid.

Equilibrium Moles

Moles of substances present at equilibrium.

Temperature Effect

Change in temperature affects equilibrium position.

Pressure Effect

Change in pressure affects gaseous equilibria.

Kp vs Kc

Kp uses partial pressures; Kc uses concentrations.

Equilibrium Shift

Change in concentration causes shift in equilibrium.

Insoluble Compounds

Substances that do not dissolve significantly in water.