Class: BE210
Group: W5
Members: Walter Aughenbaugh, Seema Patel, Matthew Samuelowitz,
Adrianne Wenisch
Date: May 7, 1999
Abstract:
The main objective of the project was to evaluate a universal indicator
that will prompt a color change at different units of pH. An already
existing universal indicator, the Yamada Universal Indicator (YUI), was
prepared and analyzed. The individual indicators that constitute
YUI were separately prepared and placed into buffered solutions of whole
number pH values from 4 to10, the range for which YUI was designed.
Spectrophotometric analysis of the resulting test solutions shows that
each of the indicators “add” at each pH value to induce the appropriate
color change. A survey was conducted to test the reliability of the
YUI in determining whole number pH values of test solutions for pH values
of 6.0, 7.0 and 8.0 ? 0.1, ? 0.2, and ? 0.3 based on the color of the test
solutions. The results of the survey show that at least 95.0% of
the participants correctly identified the nearest whole number pH of test
solutions with pH’s of 5.9-6.1, 6.7-7.0, and 8.1. Thus, the YUI has
only restricted uses in practical situations due to its limited reliability,
as defined by the 95.0% confidence limit.