Equilibrium

Question 1

Chemical equilibrium

Answer 1

• the state in which both the reactants and products are present in concentrations which have no further tendency to change with time, so that there is no observable change in the properties of the system

Question 2

Dynamic equilibrium

Answer 2

• individual particles/species are changing, but because the rates of the forward and reverse processes are equal, there is no net change in the amounts of particles/species

Question 3

Equilibrium constants (K) & equilibrium expression

Answer 3

• the equilibrium expression codes all the information about the concentration of all species into one number
• if the concentrations are at equilibrium, that number is the equilibrium constant, K

K=[reactants]^yeq/[products]^xeq

See notebook

Question 4

Qualitative interpretations of K

Answer 4

• if K»1, products dominate at equilibrium
• if K«1, reactants dominate at equilibrium
• K only changes due to temperature

Question 5

ICE tables

Answer 5

See notebook
- I is the initial concentration
- C is the change in concentration
- E is the equilibrium constant

Question 6

Reaction Quotient (Q)

Answer 6

• occurs at any time and not necessarily at equilibrium
  Q= [products]^yeq/[reactants]^xeq
• comparing Q to K will tell you which way (forward or reverse) a reaction will go spontaneously to get to equilibrium
  See notes

Question 7

I.C.E table

Answer 7

Initial concentration
Change in concentration
Equilibrium constant
See notes

Question 8

Le Chatelier’s Principle

Answer 8

1. Concentration: run shifts left or right to minimize stress & reestablish the original equilibrium
2. Volume: decreasing or increasing size of container
3. Temperature: increase or decrease heat
   See notes

Question 9

Catalysts

Answer 9

• doesn’t change the equilibrium but makes it reach it faster