Understand that the pOH scale describes the [OH-] of a solution and can be defined as: pOH = -log[OH-] and [OH-] = 10-pOH. Interconvert [H+], [OH-], pH, and pOH values.
Define a Lewis acid as an electron-pair acceptor and a Lewis base is an electron-pair donor. Apply Lewis acid-base theory to inorganic and organic chemistry to identify the role of the reacting species.
Understand that when a Lewis base reacts with a Lewis acid, a coordination bond is formed. Recall that nucleophiles are Lewis bases and electrophiles are Lewis acids. Draw and interpret Lewis formulas of reactants and products to show coordination bond formation in Lewis acid-base reactions.
Interpret the strengths of weak acids and bases as described by theirKa,Kb, pKa, or pKbvalues.
Recall that, for a conjugate acid-base pair, the relationshipKaKb=Kwcan be derived from the expressions forKaandKb. Solve problems involving these values.
Understand that the pH of a salt solution depends on the relative strengths of the parent acid and base. Construct equations for the hydrolysis of ions in a salt, and predict the effect of each ion on the pH of the salt solution. Recall the examples of the ammonium ion NH4+, the carboxylate ion RCOO-, the carbonate ion CO32-, and the hydrogen carbonate ion HCO3-.
Interpret the general shapes of pH curves for all four combinations of strong and weak acids and bases including: intercept with the pH axis, equivalence point, buffer region, and points where pH = pKaor pOH = pKb.
Recall that acid-base indicators are weak acids, where the components of the conjugate acid-base pair have different colors. Construct equilibria expressions to show why the color of an indicator changes with pH. Recall universal indicator as a mixture of many indicators with a wide pH range of color change.
Identify an appropriate indicator for a titration from the identity of the salt and the pH range of the indicator. Distinguish between the terms end point and equivalence point.
Define a buffer solution as one that resists change in pH on the addition of small amounts of acid or alkali. Describe the composition of acidic and basic buffers and explain their actions.
Recall that the pH of a buffer solution depends on both: the pKaor pKbof its acid or base, and the ratio of the concentration of acid or base to the concentration of the conjugate base or acid. Solve problems involving the composition and pH of a buffer solution, using the equilibrium constant. Explain the effect of dilution of a buffer.