Advanced Chemistry Through Inquiry Teacher Guide

(PS-2828)

Teacher manual for AP* and Advanced Chemistry labs. Has both the printed version and a flash drive with teacher tips, a PDF of teacher version and editable Word student version.

Measuring Vitamin C A Redox Titration

Lab Summary

Vitamin C, also called L-ascorbic acid, is found in many foods. Most people expect orange juice to be the best source of vitamin C but other berries have a higher vitamin C content and juice drinks like Hi-C® have a great deal of added vitamin C. In these cases, it is difficult to perform a traditional acid–base titration because there may be more than one acid present. How can we accurately measure the vitamin C content present in foods?
What foods have the highest levels of vitamin C?

Theory

Students expand their understanding of titrations, carry out a redox titration, and then use the redox titration method to answer a question of their own design.

Method

The student can design, and/or interpret data from, an experiment that uses titration to determine the concentration of an analyte in a solution. The student is able to design and/or interpret the results of an experiment involving a redox titration.

Sensors / Equipment Used:

PASPORT High Accuracy Drop Counter

(PS-2117)

Is a professional drop counter that allows students to capture detailed titration data. For use with PASPORT Interfaces.

Ammonium Ion Selective Electrode

(CI-6717)

The Ammonium Ion Selective Electrode is designed to measure ammonium concentration in an aqueous solution.

The Associated Bundle:

Chemistry Standard Sensor Bundle

(PS-2927C)

Contains the sensors and probes needed to perform all 17 experiments in the Advanced Chemistry Teacher Guide and all 25 labs in the Chemistry through Inquiry Guide.

Interface Required

This experiment may require software and an interface for data collection.