chem chapter 16

dynamic equilibrium

the rate of the forward reaction equals the rate of the reverse reaction

dynamic equilibrium is called dynamic because

the forward and reverse reactions are still occurring but at the same rate

dynamic equilibrium the two concentrations are

constant

dynamic equilibrium the two concentrations are not

equal

law of mass actions

the relationship between the concentration of the products and the reactants at equilibrium is more commonly known as the equilibrium constant expression, k

k is always _________________ and ________________ ________________

positive and temperature dependent

equilibrium constant expression, kc does not have any

units

the value of kc does not depend on

initial concentration of products or reactants

k=1

neither direction is favored and forward reaction proceeds about half way

k>1, its large and the position of the equilibrium favors the

products side (right)

k

reactant side (left)

when the reaction is written backwards, the equilibrium constant is

inverted (1/kforward)

when the coefficients of an equation is multiplied by a factor of c, the equilibrium constant is

raised to the factor of x

when you add equations to get a new equation, the equilibrium constant of the new equation is the product of the

equilibrium constants of the old equation

the concentration a gas in a mixture is

proportional to its partial pressure

if Δn = 0, then

kp=kc

heterogeneous equilibrium

applies to reactions in which reactants and products present in different phases

q is the

quotient of activities of products and reactants at any stage of a reaction

Q gives the same ratio the equilibrium gives, but for a system that is

not at equilibrium

if q>k, the reaction will proceed to the

left

if q

right

q=k

reaction is at equilibrium

according to le chatlier principle if the added or removed product is a solid or liquid it has

no affect on concentration and equilibrium

in an endothermic reaction, the heat is

on the side with the reactants

in an exothermic reaction, the heat is

on the side with the products

catalyst lower

activation energy

catalyst decrease the amount of time

taken to reach equilibrium

catalyst do not effect the

position of the equilibrium

to check if x is small, use the equation

(approximate x/initial concentration)*100

the x is small approximation is valid is

it is less than 5%