Question

3) Cerium(IV) sulfate  is used to titrate a solution of iron(II) ions, with which it reacts according to

Ce⁴⁺(aq) + Fe²⁺(aq) = Ce³⁺(aq) + Fe³⁺(aq)

A cerium(IV) sulfate solution is prepared by dissolving 38.14 g of Ce(SO₄)₂ in water and diluting to a total volume of 1.000 L. A total of 17.82 mL of this solution is required to reach the endpoint in a titration of a 250.0-mL sample containing Fe²⁺(aq). Determine the concentration of Fe²⁺ in the original solution.

answer: _______M

4) It is desired to neutralize a solution X that contains a mixture of potassium chloride and hydriodic acid. Titration of 13.2 mL X with 0.114 M silver nitrate required 51.1 mL of the latter. The resulting precipitate, containing a mixture of AgCl and AgI, was dried and found to weigh 1.230 g. How much 0.116 M sodium hydroxide should be used to neutralize 13.2 mL solution X?

______ML

5) A student has 510.0 mL of a 0.1174 M aqueous solution of KF to use in an experiment. He accidentally leaves the container uncovered and comes back the next week to find only a solid residue. The mass of the residue is 5.636 g. Determine the chemical formula of this residue.

Answer 1