Five acid-base equilibria are shown below. In each equation the two reactants on the left side of the equilibrium are designated A & B; the two reactants on the right are designated C & D. In the first equation, the charges of ionic reactants are shown; for the other four reactions these charges are omitted. In the fifth equation, H2CO3 is reactant C and NH3 is D. NaCl is an inert product. A table of pKa values is provided at the bottom of the page.
For each equilibrium, three questions are posed: