1. RICE BOXES Write a balanced chemical equation for reaction
Write in the values of the concentrations that you know in three rows under each species – initial, change, equilibrium
Initial concentration = concentration of reactants originally placed in container (product concentration is usually zero unless otherwise stated)
Change = usually a plus sign for products as they are created and a minus sign for reactants as they are used up
Equilibrium = calculated from initial ± change in concentration
Write the Kc expression and substitute in the EQUILIBRIUM values you calculated to calculate the Kc value

7. When the Kc value is very small
If the Kc value is very small (less than 10-3)
At equilibrium, there are much more reactants than products.
We can assume therefore that the initial concentration of the reactant is about equal to the reactant concentration at equilibrium.

10. Kc can be calculated from thermodynamic data