The table format that was used in this activity is very useful in equilibrium calculations. Successful solution of such problems depends on
- writing the Q expression correctly.
Remember that solids and pure liquids divided by their standard states are 1. Thus they don't appear in Q expressions.
- paying careful attention to whether to which of the given data refers to initial pressures and which refers to equilibrium pressures.
- paying careful attention to the sign and magnitude of the changes that you tabulate.
- The ratio of the changes must be the ratio of the coefficients of these substances in the balanced equation
- Substances formed in the reaction approaching equilibrium are assigned positive changes
- Substances consumed in the reaction approaching equilibrium are assigned negative changes.