2. A 0.1967 g sample of pure ascorbic acid is weighed out and dissolved in 50.0 mL of distilled water in an
Erlenmeyer flask. One week later, when about one third of the water in the flask has evaporated, this
solution is titrated against 0.01735 M KIO3 solution and requires 18.75 mL of it to reach the end point.
(a) What mass of ascorbic acid has been oxidized by the air over the weeklong waiting period?
(b) Has the concentration of the ascorbic acid solution increased or decreased as a result of the
evaporation? Show calculations to support your answer. Hint: Remember that oxidation has
occurred as well as solution evaporation.
1 answer