Errata

"The Fi rs t Proposal of a Nonclassical Carhonium Ion," by Mart in D. Saltzman (57,289 (1980))

The structures 111 and IV are incorrect. The correct struc- tures are given below

V

Book Review of "General Chemistry Examination Questions" by Johnson and Epstein (57, A195 (1980))

The answer to question 29.5 is not wrong, contrary to what was reported.

Bioactivity in Organic Chemistry Courses by Lloyd N. Ferguson (57,46 (1980))

The propoxyphene structure on Page 48 should be

"An Alternative Approach to theTraching ofSystematic Transition .Metal (:hemintry" by Brian Hathaway (56,391 (1980))

Due to a long postal strike in Ireland, the author was unable to correct the following errors before publication. Figure I

The diagram implies that chromium metal reacts directly with C1 to produce (Cr(HzO)s)Ck, whereas in fad, the divalent metal complex is generated in an anaerobic solution while the did dimer (CI(HZO)~OH)P (or perhapi a chloro derivative) is produced in aerobic solutions.

In the ehromite to chromium reaction the Ct Heat should be C + heat. Figure 2

Section (1). The equation after "Analysis CI- as AgCI" should read

Cr"' + Na202 - GOa=

CrO4= + 3Fe" - Cr"' + 3Fe1' Section (5). The color of the species is violet. The ul assignments were inverted. The correct ones for the table

helow the diagram are

U I 'TI,(F) -'Asy

"2 'TI*+(F) t4A~F

"3 ITly(P) - (AzL

Section (7). The ordinate on the diaeram should he rlA), and the lowest point should be labeled dJ.

Section (8). The first armw in the equation should point to the left, and the color of the CrIll should he violet.

7 b h k 2: CrF6 should have a past superscript "a".

The Great Plus Sign Engulfment Two articles in the October issue fell pray to a "gremlin" in the final computer output of their articles which removed all the plus signs from their equations after the authors had seen and corrected their proofs. The two articles and the correct equations are given below.

50-Minute Experiment, "An Approximate Determination of Avogadro's Constant" by Thomas Szell, David Dennis, Jean-Pierre Jouas, and Mabel Wong (57,735 (1980)) page 735, column 2, last line

[t, + t2/2]T = t°C page 736, column 1, first equation

2Ht(ag) 2e- - H2k) 2 males of ions + 2 moles of eleetons 1 mole of molecules

column 1, fourth equation

column 1, ninth equation

T = temperature of gas (273 + t°C)k

column 2, first equation under Calculations

P = 761 Torr + 359mm HzO X I 1 Torr 13.6mm HzO 1

- 22.4 Torr = 765 Torr column 2, second equation under Calculations

1 atm DT,

765 Torr X - 7fin T,,,, X 0.0434L . . . .. . -. .

,,HI=-= RT L . atm

0.082 - X (24 + 27B)K mole. K

= 1.79 X lo-:' moles HZ

Tested Demonstrations, "The Preparation and Proper- ties of Polyhutadiene (Jumping Rubber)" by Bassam 2. Shakhashiri, Glen E. Direen, and Lloyd G. Williams (57, 738 (1980)) page 739, column 1, first three equations under "Discussion" section

1.5 CsH1,C1 + 3Na - 1.5 C ~ H I I N ~ + 1.5NaCI

876 / Journal of Chemical Education