Ammonia solution is titrated with hydrochloric acid under constant-temperature conditions
CHEMISTRY · Multi-part · A Level · Chemistry · Acids and bases · Acids and bases
Problem
Ammonia solution is titrated with hydrochloric acid under constant-temperature conditions.
• Initial ammonia volume: 25.0mL
• Initial ammonia concentration: 0.100M
• Titrant (HCl) concentration: 0.100M
• Base-dissociation constant for ammonia: Kb=1.8×10−5
Parts:
(a) Determine the volume of HCl that must be added to reach the equivalence point.
(b) Write the balanced net-ionic equation for the reaction that occurs up to the equivalence point and name the conjugate acid formed.
(c) Calculate the molar concentration of the conjugate acid present immediately after the equivalence point is reached.
(d) Using equilibrium considerations, calculate the pH of the solution at the equivalence point. Show all reasoning steps clearly.