Starting with equal concentrations of all solutes, predict the direction in which the following reaction will proceed.

Question

H3PO4(aq) + HCO3-(aq) �¨ H2PO4-(aq) + H2CO3(aq)

a. left
b. right
c. no net reaction

Answer 1

Hey - just look up the Ka (or Kb respectively) values for each compound, and see which is bigger. Stronger acid = bigger Ka and that will dictate which direction it will go in. In this case, H3PO4 is the strongest acid (highest Ka) and therefore the direction of that reaction will proceed TO THE RIGHT =). Hope this helps.