Correction: Determination of the Charge Density of Silica Sols

much encouragement and advice. Contribution No. 2403. Gates and. Crellin Laboratories of Chemistry. California Institute of Technology. Pasadena, Cali...
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ADDITIONS AND CORRECTIONS

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values of (-dC/dt) against t for any given position in the vicinity of p = 1/4 should tend toward a straight line the slope of which yields kl. By making two runs a t different speeds w, both D and (Y 5 w2srH/2D = w2fHJ[(l - B ~ ’ ) / ~ R can T be determined without having to wait for equilibrium to be established. The author is grateful to Dr. R. A. Pasternak for

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bringing the problem to his attention and for giving much encouragement and advice.

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GATESA N D CRELLINLABORATORIES OF CHEMISTRY CALIFORNIA INSTITUTE OF TECHNOLOGY GIRAIRM. NAZARIAN~ RECEIVED SEPTEMBER 10, 1958 (8) The Ramo-Wooldridge Corp., LOS Angeles 45, California.

ADDITIONS AND CORRECTIONS 1956, VOL. 60

H. K. Hall, Jr. Potentiometric Determination of the Base Strengths of Amines in Non-protolytic Solvents.fi Page 65. I n Table I, pK,H20 col., entry 4, for 10.i2” read “9.72.” Page 68. I n Table VIII, omit the alternate lines reading: Ell2 = 580.0 78.3 mv. pK. I .11 = 534.7 94.2 mv. pK, I .07 El/, = 575.4 82.7 mv. pKa f .09 E l / , = 554.2 79.8 mv. pKa I .13 H. K. HALL,JR. Robert B. Anderson, W. Keith Hall, James A. Lecky and Karl C. Stein. Sorption Studies of American Coals. Page 1558. In col. 2, line 2 of paragraph number 4., for 4nhibition” read “imbibition.”

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1957, VOL. 61

R. W. Ramette and T. R. Blackburn. The Acid Dissociation Quotient of 3-Hydroxyl-1,3-diphenyltriazine. Pages 378-379. Throughout this paper and in the earlier papers cited, by N. C. Sodani and S. C. Bhattacharya (Anal. Chew., 28, 81-83, 1616-1618 (1956)), “-triazine” should read “-triazene.”-R. W. RAMETTE. Sigmund Schuldiner and James P. Hoare, An Electrochemical Stud of Hydrogen Producing Reactions Catalyzed by Gold and 6old-Palladium Cathodes Page 705. I n the second paragraph a reference is made to Vogt and others to the effect that a t an Au/Pd atom ratio of 0.6, the paramagnetic susceptibility of the alloy went to zero. Sixty (60) atom per cent. gold should be substituted for the 0.6 atom ratio in this paragraph. The fact that there is an effect on both the mechanism of the hydrogen producing reaction, and on the rate of change of the catalytic activity a t about an Au/Pb atom ratio of 0.6, as is shown in Figs. 1 and 3, respectively, remains valid. However, the explanation given that this effect was owing to the gold in excess of the 0.6 atom ratio not contributing electrons to the d-band of the Au-Pb alloy apparently is not correct. In the second aragraph of a more recent paper (J. P. Hoare and S. Scfuldiner, THISJOURNAL 62, 229 (1958)), the statement ‘ I . to an atom ratio 0.6.” should be substituted by “. . to 60 atom per cent. gold.” The authors are indebted to Prof. W. G. Burgers, Delft Technical Institute, and to Dr. J. E. Goldman, Ford Scientific Laboratories, for bringing this point to their attention.S. SCHULDINER. L. B. Nanninga. Formation Constants and Hydrolysis a t 100” of Calcium and Magnesium Complexes of Adenosine Tri-, Di- and Monophosphate. Page 1144. A statement was made on p. 1145 that Martell and Schwarzenbachg imply that KHZ = KHMZ. This must be withdrawn, as under their conditions of excess M,

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Vol. 62

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(ZH MHZ)/(H)(Z MZ) is a constant also for KHZ # KHMZ. This criticism therefore was based on a wrong conclusion. Furthermore, their value for CaATP of 4000 (pK 3.60) becomes after correction with the factor 1 10 (Na), 8000 instead of 12000. The fact that potassium was used instead of sodium does not change this factor, as according to Melchiorll sodium and potassium bind in the same way to ATP.-L. B. NANNINGA. G. H. Bolt. Determination of the Charge Density of Silica Sols. Pages 1167-1168. By multiple oversight figures and legends were not printed properly and should be: Fig. 1.-(Fig. 2 as printed) Titration curves of “Ludox” colloidal silica as obtained by using an agar bridge containing a concentration of electrolyte e ual to that of the sol. Fig. 2.-(Fig. 1 as printed) %itration curves of “Ludox” colloidal silica as obtained by direct immersion of the calomel-KC1 (satd.) reference electrode. Fig. 3.-Suspension effect in “Ludox” suspension: The readings for 0.001 and 0.004 N NaCl were obtained in two different ways (see text). For Insert: Silicate ion concentration as a function of the pH, calculated on the basis of p K = 9.8 and a solubility of undissociated silicic acid equal to O.Ol%.-G. H. BOLT.

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1958, VOL. 62

Elias Klein, John B. McKelvey and Beverly G. Webre. The Simultaneous Measurement of Distribution Coeficients and Hydrolysis Rates. Page 286. In col. 2, e (2), the denominator of the last ~ ~MCKELVEY. part should read “KVo + C t w . J ’ - J ~ B. B. Roger Ray, J. R. Anderson and J. J. Scholz. Wetting of Polymer Surfaces. I. Contract. Angles of Liquids on Starch, Amylose, Amylopectin, Cellulose and Polyvinyl Alcohol. Page 1220. I n line 9 of the Abstract, for “42” read “44.” Page 1224. I n col. +,line 4 from the end, for “Angles of .” read “Angles on.

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J. J. Scholz, B. Roger Ray and J. R. Anderson. Wetting of Polymer Surfaces. 11. Contract Angles of Liquid8 on Esters and Ethers of Amylose and Amylopectin. Page 1227. I n the Abstract, lines 3 and 4 should read: “polymer against the surface tensions of the li uids yields characteristic lines. Hysteresis effects (10-303 result in two.” Page 1230. I n col. 1, next to last line, for “swelling” read “spreading.” John H. Saylor and Rubin Battino. The Solubilities of the Rare Gases in Some Simple Benzene Derivatives. Page 1335. I n col. 1, line 8 from the end, the equation should read “(log L = -0.02210~ 0.025).”--5. H. SAYLOR. R. W. Atteberry. Kinetics of Hydrolysis of Decaborane. Page 1458. I n col. 1, line 1,for “slower” read “faster.”R. W. ATTEBERRY.

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