Calculating Equilibrium Concentrations
Type 1: Given initial concentrations and one equilibrium concentration
- Write balanced, dissolution equation →Set up ICE table below
- I: initial concentrations
- C: Change in concentration
- E: Equilibrium concentrations
- Solve for x
- If question doesn’t state molarity of substance, assume that it is 0
Type 2: Given initial concentrations and K
- Find Q using inital concentrations and compare to K
- Q < K → reactants will have –nx and products will have +nx (products/forward reaction favored)
- Q > K → reactants will have +nx and products will have –nx (reactants/reverse reaction favored)
- If k is very small can assume that x is insignificant
- Shortcut using calculator
- Y1 = value of K
- Y2 = plug in entire equilibrium equation
- Graph → 2nd Trace → #5 → don’t move cursor → enter x3
- X-value will be the answer for x
- Plug in value for x