rent practice, but these are not the audience for undergraduate experiments. Such workers require graduate-level training with rigorous attention to the limitations of the theory. This is not to say that there are no useful calculations that should be included in general analytical courses. The calculation of reouired column leneth from a chromatoeram with " inadequate resolution, the extrapolation of the retention times of homologous series, the use of the slope of the log plot, the prediction of necessary column loading when changing to a solid support of different density, calculations on columns in series and some of the more recent systems for predicting optimal compositions of mobile liquids are all simple enough and give correct enough answers to warrant our students' time. But measurement of thevan Deemter constants should have no place in undergraduate texts or laboratories or in most graduate curricula.
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EDUC., 59,290 (1982). 'Moody, H. W., J. CHEM. Stephen J. Hawkes Oregon Stale University Corvaliis, OR 97331
Note to: Method for Balancing Redox Reactions Containing Hydroxyl Ions To the Editor: The method presented by Pernicone [J. Chem. Educ., 58, 966 (1981)l obviously works, and works well; I think, however, there is a much simpler way of balancing these reactions and, what seems to me more imnortant. of masterine and remembering them. After havine identified the half-cells and written them down, performuthe following steps
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1)Balancing the Oxygen: For every oxygen in excess on one side of
the equation put: one Hz0 on the same side and 20H- on the other side. 2, Balancing the Hgdrogm. For every hyrogen in excess i m one srde drhe equntion put one OH- on the same ude and one H200n the other side If hydrogen and oxygen are in excess on the same side, then simply balance by putting OH- on the other side of the equation. Example I
Butanol Safely Hazard To the Editor:
Mn0,-
(MnOc + MnOz) + 2MzO + 3e- t MnOz + 40H-
Example 2 Distillation of an aged sample of 2-butanol led to an explosion in our organic chemistry laboratory on March 29, l9R9
The student performing the distillation had been issued 50 mL of 2-butanol as an unknown, had distilled all but a few milliliters. and was reaching to turn off the variable voltaee control to the heating mantle when the distillation resid;e exploded with a loud report. Although not seriouslv iniured. the student suffered mukiple cuts o
