At 25 °C a solution is prepared that contains equimolar amounts of and in water
CHEMISTRY · Multi-part · A Level · Chemistry · Acids and bases · Acids and bases
Problem
At 25 °C a solution is prepared that contains equimolar amounts of HS−(aq) and H2PO4−(aq) in water. Both ions are amphiprotic.
Using chemical reasoning based on relative acid strengths, address the following.
(a) Predict the direction (forward, reverse, or essentially no reaction) of the proton-transfer process that occurs when HS− and H2PO4− are mixed in water.
(b) Write the balanced net-ionic equation for the favored proton-transfer reaction, if any.
(c) Label all conjugate acid–base pairs in the equation from part (b).
(d) Using Ka or Kb values (numerical data not required), justify in detail the prediction made in part (a).