A N A L Y T I C A L   C H E M I S T R Y  2 5 6
R O L E - P L A Y I N G  L A B

1998-1999 Academic Year
© Prof. John P. Walters
St. Olaf College
Northfield, MN 55057

Introduction to Role-Playing and Laboratory Computing
Defining the Kinds of Role-Playing Responsibilities
Round-Robin Certification of Laboratory Glassware
Production Quality Control Lead Analysis
Statistical/Chemical Evaluation of Lead Data

Semi-Automated Weak Acid Titration

Graphical Analysis of Weak Acid Titration
Designing a Mock Robot Experiment
Executing the Mock Robot Experiment
The Incredible Edible Easter Egg Grass Advertising Dilemma
The Downsizing Dilemma
The Broken Pill Coating Machine Assembly Line Shutdown Dilemma
The Instrument Purchase Payment Release


Manager: Organization of the Weak Acid and Standardization Titrations
Chemist: Preparation and Standardization of the Strong Base Titrant and Weak Acid Titrate
Software: Operation of the all LabVIEW Virtual Instruments and doing F-Test Statistics
Hardware: Calibration of the FET Electrode and Setup of the Semi-Automated Titration Device.


The central objective is to gather enough of the right kind of data to use next week with a LabVIEW simulated titration to determine if some fundamental solution properties are important enough to be consequential when a titration is used as an analytical tool. A second objective is to prepare a base solution, with a known molarity and precision, and then learn if its reliability can be estimated with a statistical F-test made between Companies. A third objective is to assemble FET pH sensing electrode and digital voltmeter with an electronic top loading balance and "chicken feeder" base delivery system, and a LabVIEW based computer titration display to do a semi-automated titration in the following lab period.


There are two parts to this week’s interview. The first concerns Manager's assessment of how well the standardization went in producing a good NaOH molarity. Of interest is how well Software prepared a base standardization spreadsheet, how well the F-test went, and how well Hardware calibrated a voltmeter to read pH and then assembled the semi-automated titration apparatus.

The second part is what Manager plans to do in the next week to conduct the weak acid titration and gather data for the LabVIEW simulation to reveal and analyze the effects of ionic strength, pKa values, pKw value, base standardization accuracy, temperature, and initial titration volume, and amount of base delivered during the titration. Of special concern will be how the Company people plan to aid Manager in assessing the consequentiality of all these variables on the accuracy that could be expected if the titration were used to assay the weak acid purity.