**Calculations involving Chemical Equilibrium**

For solving most problems relating to finding equilibrium moles and equilibrium constant the following steps can be followed;

- Set up a table of moles of each species on equilibrium stating initial (starting) moles, change of moles in terms of a, and equilibrium moles involving a.
- If partial pressures are to be found, calculate the total moles (involving ‘a’) at equilibrium, and hence the mol fraction of each species.
- For calculating K
_{e}the values of the equilibrium concentrations in mol calculated from step 1 are to be substituted in the appropriate expression for K_{e}. - For calculating K
_{P}, the mol fraction of each species obtained in step 2 is multiplied by the equilibrium pressure to obtain values of partial pressures of the components in the mixture. Substitution of the partial pressure values in the appropriate expression for K_{P}gives the result.