Powdered limestone (largely CaCO₃) is reacted with 50.0 mL of 0.200 M HCl
CHEMISTRY · Multi-part · A Level · Chemistry · Acids and bases · Acids and bases
Problem
Powdered limestone (largely CaCO₃) is reacted with 50.0 mL of 0.200 M HCl. After the solid has completely dissolved and CO₂ has been released, the clear solution is titrated with 0.150 M NaOH. It requires 31.2 mL of the NaOH solution to reach the equivalence point. Immediately afterward, the analyst accidentally delivers an additional 3.00 mL of the same NaOH solution.
Assume ideal behavior and additive volumes.
(1) Write the balanced net ionic equation for the neutralization reaction that occurs during the titration step.
(2) Calculate the number of moles of HCl that remained in solution after reaction with CaCO₃ but before any NaOH was added.
(3) Determine the concentration of OH⁻ in the flask after the accidental extra 3.00 mL of NaOH is delivered.
(4) Calculate the pH of the final solution in the flask.