Addendum: Conventions defining thermodynamics - Journal of

Addendum: Conventions defining thermodynamics. Richard M. Noyes. J. Chem. Educ. , 1963, 40 (3), p 116. DOI: 10.1021/ed040p116. Publication Date: March...
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Graduate Placement Test in Physical Chemistry Form 1961P was prepared by a subgroup consisting of

J. D McCullough, UCLA, Chairman R A Alberty, Wisconsin C. N. Cauehlan. Montana State

Twenty items are included; all are of the multiple-choice answer type. Ninety minutes is the prescribed time. Fnndamental thermodynamic principles loom large; equilibrium, kinetics, electrochemistry, and other major areas are represented. A student also must have a thorough underatanding of how information a t the moleculiir level can be used to anticipate macroscopic properties.

Condensed Norms Scoring formula Maximum possible score Percentile rank 99 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25

Organic Chemistry Form 1962 Form 1962 follows the same format as the 1958 form. Five possible responses are given for each question. Part one (50 items, 50 min) deals with monofunctional aliphatic compounds. Part two (50 items, 50 min) covers aromatic compounds, polyfunctional compounds, and natural products. At least 15% of the 100 items deal with material which has only lately entered the introductory organic chemistry course. The new form gives greater emphasis to such content as correlations of physical properties t o structure and reaction mechanisms. Two or three items reflect very recent entries into the descriptive portion of the course.

Condensed Norms Scoring formula Maximum possible score

R-W/4 100

Percentile rank 99

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15 10 5 1 Reliability coefficient The figures given are raw scores. The reliability coefficient was estimated by the Kuder-Richardson Formula No. 21.

20

15 10 5 1 The figurea given are raw scores.

The monn consists of 763 students who took the test a t the completionof a one year course in o r ~ a n i cchemistrv. The

The group consisted of 522 first year graduate students from 22 institutions.

Addendum: Conventions Defining Thermodynamics Professor Albert Sprague Coolidge of Harvard has called my attention to an ambiguity in my paper on "Conventions Defining Thermodynamic Properties of Aqueous Ions and other Chemical Species" (THISJOURNAL, 40, 2 (1963)). The entries for gaseous ions in Table 2 were based on entries in Bureau of Standards Circular No. 500. Although the conven-

Hence it includes (5/2)RT for the translational energy a n d P V work associated with creating the gaseous electron even though the electron is not mentioned in the entry. Similarly, the entry in Circular No. 500 for AH,' for gaseous rhloride ion is really AHo for the reaction

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I thought they were, and since it is essential that contributions from gaseous electrons be separated if reactions of Type G are to be discussed, the entries in Table 2 of mv naner must be chanced. For every positive gaseous ion of charge -\-z, values of £^H and of AF,? in Table 2 should be made less positive by 1.481~ kcal/mole; for every negative gaseous ion of charge -2, the values should be made less negative by the same amount. If these changes are made, the entries in Table 2 will be consistent with the text of the paper. If these changes are made, values of AHu' and of ^Fn' in equations (35) and (36) of my paper must also be reduced 1.48 kcal/mole. As will be pointed-out-in-a forthcoming paper in the Journal of the American Chemical Society, these thermodynamic changes for reaction (34) assume that the electron in state e-(0) is in a medium a t the bulk electrostatic potential of water rather than in vacuum. The distinction is only important when "absolute" electrode potentials are being considered. M.NOTES RICHARD