Steps For Equilibrium Calculations

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1. List the major species in the solution ( I usually draw a picture of a bucket including species).

2. Find the species that produces H⁺ (or OH^1-) and write the balanced equation including equilibrium constants.

Don't forgot to include the auto-ionization of H₂O₁.

3. Using the values of the equilibrium constant for the reactions you have written, decide which equilibrium (or coming to completion) will dominate in producing H⁺ or OH^1-.

4. Write the equilibrium constant expression for the dominant equilibrium.

5. Then following the ICE box method ( If you don't have look below).

5a. If needed, change mole into molarity (M). and state the initial conditions (into the ICE box).

5b. Figure out change and where "-" and "+" sign need for "x", Use Q if needed.

5c. Find equilibrium concentration as equation.

5d. Fill in the equilibrium constant expression with the appropriate number and/or equation.

5e. Solve mathematically (with calculator) or try the 5% rule simplification.

5f. Solve for "x" and then determine equilibrium concentrations for all species especially H⁺ and/or OH^1-. If used 5% rule, check to make sure it is appropriate.

6. Once have the [H⁺] or[ OH^1-], then calculate pH or pOH as required.