— 183°, contains more ortho-H2 than the equilibrium mixture, probably owing to the ortho- being more strongly adsorbed than para-H2. Continuous removal of H„ at —183° in the range 7—25 cm. shows no definite change (within 1 %) in the relative adsorption.
J. G. A. G.
Theory of heat evolved in capillary condens
ation. E. H u c k e l (Trans. Earaday Soc., 1932, 28, 382—386).—A thermodynamic treatment for adsorb
ents with capillaries of sufficiently large diameter.
J. G. A. G.
Derivations from “ ideal ” translational motion of adsorbed molecules. M. G. E v a n s
(Trans. Faraday Soc., 1932, 28, 364—368; cf. A., 1931, 903).—Mathematical. Effects of “ active points ” in retarding the mobility of a two-dimensional gas film are considered. The equation developed is consistent with existing data for sorption sufficiently removed from saturation. J. G. A. G.
Migration of adsorbed molecules on surfaces of solids. M. V o l m e r (Trans. Faraday Soc., 1932, 28, 359—363).—A survey. J. G. A. G.
Processes of adsorption and diffusion on solid surfaces. J . E. L e n n a r d - J o n e s (Trans. Faraday Soc., 1932, 28, 333—359).—Theoretical. From a quantum-mechanical treatment of the van der Waals forces between a metal surface and adsorbed gases, the following heats of adsorption on Cu are calc.:
A, 6000; N2, 2500; and H2, 1300 g.-cal. per mol., which are of the same order as those observed experi
mentally at low temp. Adsorption at crystal surfaces is examined in greater detail (cf. A., 1928, 8).
The case in which the cohesion between a metal and the individual atoms of an adsorbed gas mol. is greater than the dissociation energy of the mol. may be identified with “ activated” adsorption (A., 1930, 990; 1931, 902). Consideration of the behaviour of an atom on a metallic surface which is traversed by cracks and of wliich the potential field varies from point to point affords an activated diffusion mechanism for slow adsorption consistent with the results of Ward (A.,
1931, 1365). J . G. A. G.
Nature of activated adsorption. G. B. K i s t i a - k o w s k y (J. Amer. Chem. Soc., 1932, 54, 1693—1694).
—Taylor and Sickman’s results (this vol., 458) indicate that activated adsorption is limited to particular surface atoms, the adsorbed mols. not having two degrees of freedom. The structure of surfaces may be studied by measuring heats of adsorption for varying amounts at low and high
temp. C. J. W. (c)
Suggested existence of activated adsorption.
A. F. H. W a r d (Trans. Faraday Soc., 1932, 28, 399—
405; cf. A., 1931, 1365).—Dissolution of the gas in the adsorbent accounts for the phenomena attributed to
“ activated adsorption ” (this vol., 331) and objections to the dissolution theory are met. True adsorption must have a finite, although small, energy of activation, and it is considered unlikely that the same process could take place in either of two ways with two different energies of activation. J. G. A. G.
Mechanism of the adsorption process at the surface of heteropolar crystals. B. T e z a k (Kol- loid-Z., 1 9 3 2 , 59, 1 5 8—1 6 2 ) .—A scheme representing adsorption of electrolytes at a heteropolar cryst.
surface is devised, in which similarity between the ions of the electrolyte and the crystal plays a leading role. The adsorbability of an ion increases with its similarity to an ion composing the space lattice; e.g.,
with BaS04 as adsorbent the following order is observed : Ba” > Hg” > P b "> Cd" > M n"> Zn">
Cu">N i” > M g "> A l"\ When the solution con
tains an ion wliich is also in the crystal space lattice, the adsorption of the oppositely-charged ion is greater the more insol. is the compound which it forms with the common ion. BaS04 as adsorbent in a solution containing excess of Ba" takes up anions in the follow
ing order: Fe(CN)G"">Fe(CN )6" '; N03'>C1'>
B r'> I'. E. S. H.
Errors in thermal measurements. W. E.
G a r n e r (Nature, 1932, 129, 832).—A discussion of the precautions necessary in measurements of heats of adsorption and of the use of thermocouple calori
meters (cf. this vol., 592). L. S. T.
Activated adsorption of hydrogen. H. H o l l - i n g s and R. H. G r i f f i t h (Nature, 1932, 129, 834).-—
The adsorption of H2, C6H14, cycZohexane, and C6HG on metallic oxides has been measured at temp, up to 450°. Extensive “ activated ” adsorption of H2 occurs with the oxides of Mo, V, Cr, and W, and with metallic Sn and Cd. Adsorption of hydrocarbons takes place with every metal or oxide (Cr, Ti, Fe, Cu, Mo, Zn, Cd, Ca, Zr, Mg, Sn, Co, Al, Mil, and W) examined.
The velocity and extent of adsorption are con
siderably influenced by impurities. L. S. T.
Gaseous adsorption. III. Thermal activ
ation effect in the adsorption of hydrogen on platinum and nickel. E. B. M a x t e d and N.
H a s s i d (J.C.S., 1932, 1532—1539).—Thermal activ
ation has been studied quantitatively by exposing Pt and Ni to H2 at temp, other than that at which the adsorption is measured. When exposure is made at higher temp, there is an increased adsorption on subsequent cooling, which is often greater than the normal adsorption for any point within the temp, range. This effect decreases as the adsorption temp, is raised. Thermal activation does not influence the
G E N E R A ! , P H Y S I C A L , A N D IN O R G A N IC C H E M IS T R Y . 6 8 9
reversible adsorption (that part which can be re
covered by degassing at the adsorption temp.). The effect may be attributed to adsorption at an energetically heterogeneous surface. E. S. H.
Adsorption of mercury vapour by active car
bon. A. M. Ag ü e s (Anal. Fis. Quim., 1932, 30, 260—266).—Two specimens of active C adsorbed about 0-4 mg. per g. of Hg vapour from air saturated at room temp. The activity of the adsorbent could be restored repeatedly and almost completely by heating the C in a current of dry air at 160° or in
superheated steam. H. F. G.
Sorption of gases by copper. A. F. Be n t o n
and T. A. W h i t e (J. Amer. Chem. Soc., 1932, 54, 1373—1390).—The sorption by reduced Cu was measured at pressures up to 1 atm. down to —195°.
With N2 there is only rapid physical adsorption, with a small fieat effect. With H2 at lo\v temp, only physical adsorption occurs, at 78-5° activated adsorption predominates, and at 0° both activated adsorption and dissolution occur. With CO there is both physical and activated adsorption, together with either dissolution or a second type of activated
adsorption. S. L. (c)
Action of mixed catalysts in the decomposition of nitrous oxide. II. Determination of surface of catalysts by adsorption of dyes. G. M. Sc h w a b
and H. Sc h u l t e s (Angew. Chem., 1932, 45, 341—
347; cf. A., 1930, 1257).—The adsorption of methyl - ene-blue and ¡3-naphthol-orange from HaO and of anthracene-blue from cycZohexanone by CuO, granul
ated ZnO and MgO and their mixtures, and Xi powder reaches a temporary equilibrium, but further adsorption occurs. The equilibrium amounts con
verge to a saturation val. with increasing concn.
of the dye. The adsorbent surface can be calc, from the data. Surfaces which are changed by H20 can be measured by using non-aq. solvents, and by a proper choice of dyes the partial surface of a mixed adsorbent can be determined. The mixed catalysts for the decomp, of N20 formerly described have an enhanced catalytic activity without showing a marked increase of surface. Measurements of the surface of Ni by the adsorption method agree satisfactorily with those obtained from the velocity
of dissolution. E. S. H.
Comparison of adsorption of nitropbenol and iodine by vacuum-sublimed films of barium chloride. J. H . d e Bo e r [with L . A. H. Wo l t e r s] .
(Z. physikal. Chem., 1932, B, 17, 161—171; cf.
this vol., 569).—Since the max. no. (i i ) of I2 mols.
which the surface can hold is equal to twice the no.
of alizarin mols. which react with it, and each alizarin mol. displaces two CT ions, n corresponds with a unimol. adsorbed layer, every adsorbing centre being occupied. The max. no. of o-nitroplienol mols.
adsorbed from the vapour at room temp, is approx.
l'8n, and to avoid the conclusion that a bimol. layer is formed it must be supposed that the adsorbing centres consist of the surface Cl' ions together with an equal no. of points located between them; when the amount of adsorbed nitroplienol is a max., 90%
of these are occupied. p-Nitrophenol can occupy
at most only 50% of the centres, perhaps because the dipole moment of the N0 2 group opposes the adsorptive binding of the OH group. R. C.
Discontinuity of isotherms for adsorption of phenol from solution. R. Ch a p l i n (J. Physical Chem., 1932, 36, 909—912).—Stepped curves were obtained for the adsorption isotherms of PhOH by an active C from aq. solutions containing 0-1—24-0 g. per litre at 25° and 60°. P. T. N. (c)
Adsorption of electrolytes by crystal surfaces.
V. Adsorption of the solvent. (Ml l e.) L . d e Br o u c k e r e (Bull. Acad. roy. Belg., 1932, [v], 18, 361—368).—The quantities of H20 and KC1 adsorbed by BaS04 from aq. KC1 have been determined. The results suggest that the BaS04 becomes completely covered with a unimol. layer, the proportion of H20 and KC1 mols. depending on the concn. and temp."
D. R. D.
Effect of adsorbed oxygen on adsorption of electrolytes by activated carbon. O. Br e t-
s c h n e i d e r (Z. physikal. Chem., 1932, 159, 436—
440).—The adsorption of dissolved succinic acid by activated C containing adsorbed 0 is slightly increased by removal of adsorbed gas. The adsorp
tion of HC1 is reduced, the two isotherms running parallel except at low equilibrium concns.; the probable explanation is the removal by evacuation of a C oxide present on the surface. R. C.
Adsorption of thorium-JY by ferric hydroxide at different p H. I. Ku r b a t o v (J. Physical Chem., 1932, 36, 1241—1247).—The pptn. of Ra with Fe(OH)3 in alkaline media depends on the formation of a salt-like compound in which Ra acts as a cation and Fe(OH)3 as an anion. At -¡hi > 7 Th-X is firmly adsorbed by Fe(OH)3, but at lower p u there is free exchange with the solution. To obtain highly emanating preps, neither S04" nor HC03' is necessary, but the solubility product of the pure Ra salts or isomorphous Ba-Ra salts should not be exceeded in
the solution. H. F. J . (c)
Reversal of Traube’s adsorption rule. Ad
sorption of fatty acids by powdered gold in different solvents. E. He y m a n n and E. Bo y e (Kolloid-Z., 1932, 53, 153—157).—The adsorption of fatty acids in H20, C6Hfl, EtOH, and COMe2 by powdered Au decreases with increasing mol. wt. of the acid, although the decrease is not regular.
E. S. H.
Adsorption of sugars and nitrogenous com
pounds. V. Kn i a s e f f (J. Physical Chem., 1932, 36, 1191—1201).—In the adsorption of sugars by norit equilibrium is reached in a few min., but fuller’s earth requires more than 1 hr. The earth adsorbs sugars selectively, but norit does not. Reduction of p a increases the adsorption of lactose by norit and of glucose by the earth, but lessens the adsorption of lactose by the earth. In the adsorption of caffeine by the earth, equilibrium is reached with a few minutes’ shaking and is independent of the p u , and more caffeine is adsorbed from aq. than from EtOH solution. The p n is shifted by an amount pro
portional to the wt. of earth, and the disperse phase contains Ca, the amount being small and apparently
690 B R IT IS H C H E M IC A L A B S T R A C T S .— A .
independent of both p K and the wt. of caffeine ad
sorbed. The adsorption of piperidine and CO(NH2)2 by the earth has been examined. F. E. B. (c)
Absorption of silver oxide by oxides and tbeir compounds at high temperatures. I. W e s t e r - m a n n (Z. anorg. Chem., 1932, 206, 97—112).—Si02, A1203, or kaolin, after being heated -with Ag powder in presence of air, contain varying quantities of Ag chemically combined. In all cases the max. absorp
tion occurs at about 1050°, and amounts to 0-16, 0-45, and 0-40%, respectively. The amount of com
bined Ag can be increased by increasing the partial pressure of 02. In the case of kaolin an equilibrium is reached, depending on the proportion of Ag in the mixture. The rate of absorption can be expressed as a bimol. reaction. F. L. U.
Sorption of water vapour by cellulose and its derivatives. III. Heat of adsorption of water vapour by cellulose acetates. P. T Ne w s o m e
and S. E. Sh e p p a r d (J.' Physical Chem., 1932, 36, 930—938).—The adsorption isotherms for cellulose acetate sheet have been determined at 30°, 40°, and 50°, the H20 adsorption decreasing with rise in temp, at all humidities. The calc, heats of adsorption for 30—40° and 40—50° decrease with increasing H20 content of the acetate. The heat of adsorption at 25° determined calorimetrically is considerably less than the vals. calc, from the 20° and 30° isotherms.
The heat of adsorption of H20 vapour for cellulose triacetate with 44-S% Ac is less than for acetate
with; 38% Ac. P. T. N. (c)
Sorption of gases by silica gel. J. Sa m e s h i m a
(Bull. Chem. Soc. Japan, 1932, 7, 133—135; cf. A., 1931, 1120).—The sorption velocities of NH3, C02, and C2H4 on Si02 gel have been measured at 25° and atm. pressure, over an interval of about 60 days.
90% of the extreme sorption observed is reached in
2—10 min. F. L. U.
Base exchange in permutite and surface ad
sorption b y silicic acid gels. E. G r ü n e r (Chem.- Ztg., 1932, 56, 208). I. R. H a a s (ib id ., 353).—
Polemical (cf. this vol., 337). E . S. H.
Formation and properties of precipitates.
Theory of co-precipitation. I . M. Ko l t h o f f
(Chem. Weekblad, 1932, 29, 307—310).—A discussion of adsorption of ions by ppts. A ppt. will adsorb ions similar to those which it contains if they exist in excess in the solution; only at a definite ionic activity is the thermodynamic potential zero. The adsorption of Ba salts and K2S04 by BaS04 and the potentiometric determination of ionic activities are
discussed. H. F. G.
Persorption and unimolecular sieves. J. W.
M c B a i n (Trans. Faraday Soc., 1932, 2 8 , 408—409).—
The difference between “ persorption ” and true solution is emphasised (cf. A., 1930, 990), and the relation to mol. sieves is discussed (cf. ib id ., 728).
J. G. A. G.
Liquid-vapour interface. J. L. Sh e r e s h e f s k y
(J. Physical Chem., 1932, 36, 1271—1278).—An equation is derived for the adsorption of a vapour on its own liquid phase. For C6H6 from m. p. to
b. p. the heat of adsorption is 1365 g.-cal. per mol., and the thickness of the adsorbed layer is 1-0 X lO8 cm., which < the mol. diameter. At corresponding temp, the “ mol. adsorption ” is the same for all
vapours. F. E. B. (c)
Thermodynamical study of the variation of surface tension of a surface of contact between two phases with the composition. Conceptions of true and apparent surface concentrations. L.
Ga y (J. Cliim. pliys., 1932, 29, 97—107).—Measure
ments of the variation of surface tension with com
position lead to the apparent (not the true) surface conen. Under certain conditions the true surface
concn. may be calc. E. S. H.
Surface tension of various aliphatic acids pre
viously studied for bactericidal action on M y c o b a c t e r i u m l e p r œ . XX. W. M. S t a n l e y and R.
A d a m s (J. Amer. Chem. Soc., 1932,54,1548—1557).—
The surface tension, y, of aq. and media solutions of the Na salts of 120 such acids has been determined.
Every bactericidal acid markedly depresses y . The val. of y is high for the salts of acids of low mol. wt., but, irrespective of structure, decreases with increas
ing mol. wt. and then begins to increase slightly when the no. of C atoms reaches about 19. With certain a-hydroxy-fatty acids y increases with the mol. wt.
Ring structure increases y slightly compared with the corresponding straight-chained acids with the
C02H group within the chain. Introduction of an i.so-group slightly increases y, whereas a double linking in the ring or C chain has no appreciable effect. Shift of the C02H group to the second C atom causes a very large drop in y, but as it moves farther down the chain y increases slightly and then decreases slightly as it reaches the middle C atom. C. J. W. (c)
Behaviour of dyes and silver sols during mea
surement of surface tension. T. R u e m e l e (Z.
physikal. Chem., 1932, 160, 8—14).—The surface tensions of aq. solutions of various dyes and the effect of K halides on the surface tension of night-blue solutions have been determined. The surface tension of a Ag sol prepared by development of a nuclear sol increases with diminution in the amount of the latter, but the surface tension of the ultra-filtrate is always
equal to that of H20. R. C.
Capillary electric phenomena and the wetting of metals by electrolyte solutions. A. Fr u m k i n,
A. Go r o d e t z k a j a, B. Ka b a n o v, and N. Ne k r a s s o y
(Physikal. Z. Soviet Union, 1932, 1, 255—284).—
The relation between the p.d. solution/Hg and the contact angle of the three-phase lines solution-Hg-gas and solution-Hg-oil is discussed. The applicability of Neumann’s equation to the former system is vitiated by the presence of an adsorbed film of HA) containing electrolyte between thé Hg and a gas bubble. The readiness of wotting of surfaces of Ag and of PbS by solutions is increased by c a th o d ic
polarisation. J. W. S.
Determination of adhesion tension of liquids against solids. Microscopic method for mea
surement of interfacial contact angles. F. E.
Ba r t e l l and E. J. Me r r i l l (J. Physical Chem., 1932, 36, 1178—1190).—The validity of the assumptions
G E N E R A L , P H Y S I C A L , A N D IN O R G A N IC C H E M IS T R Y . 691 underlying the determination of contact angles by
measuring the pressure set up by H20 displacing an org. liquid from a powder has been tested. Liquid- air-solid and H20-org. liquid-solid contact angles have been determined from measurements of enlarged images obtained by optical projection of photomicro
graphs of the interfaces in capillary tubes. The former angles usually decrease in the order Si02>
pyrex glass>Pb glass>soda-lime glass. In the liquid- liquid-solid experiments it was observed that droplets of HoO appeared between the org. liquid and the wall, the former ultimately being completely enveloped by an H o O film, at which point the contact angle became 0°. Vais, for adhesion tensions calc, from the above contact angle data agree sufficiently closely with those obtained by the method of fine pores to justify the
latter method. F. E. B. (c)
Surface tension of flour suspensions. T . R u e - m e l e (Kolloid-Z., 1932, 59, 151—152).—The surface tension of suspensions of flour in aq. lactic acid, AcOH, and H2C204 (2N—O-OOIA1) increases as the concn. of acid decreases and is lower for good than for poor
kinds of flour. E. S. H.
Energies of immersion of silica in liquids.
F. E. B a e t e l l and E. G. Almy (J. Physical Chom., 1932, 36, 9S5—999).—The relation between free and total energy of wetting, measured by the adhesion tension and the heat of wetting, respectively, has been obtained. The relative total energy of wetting for various liquids is independent of the source of the Si02 gel for the methods of pptn. used. Vais, of heat of wetting calc, with an assumed area for the gel agree with the observed vals. R. H. L. (c)
Gum surfaces. I. F. V. v o n H a h n (Kolloid- Z., 1932, 59, 130—135).—When a drop of aq. dye solution containing a surface-active substance is placed on the surface of a gummy material, it spreads to an extent which decreases with increasing age of the surface, but is independent of the naturo of the gum. The figures produced by the spreading are
sp. for each gum. ” E. S. H.
Capillarjr systems. XIV. Dynamics of os
motic cells. E. M a n e g o l d and K. S o l e (Kolloid- Z„ 1932, 59, 179—195).—Theoretical. E. S. H.
Blocking phenomena in ultrafilters. F. E r b e (Kolloid-Z., 1932, 59, 195—206; cf. this vol., 461).—
The permeability of a membrane for different liquids depends on the thickness of the layer of mols. of liquid lining the capillaries. The phenomenon is related to the varying sedimentation vols. of suspensions.
E. S. H . O sm osis in s y s te m s c o n sistin g of w a ter and tartaric acid . I. F. A. H. S c h r e i n e m a k e r s and
J . P. W e b r e (Proc. K . Akad. Wetensch. Amsterdam, 1932, 35, 42—50).—The theory developed previously (cf. A., 1931, 422, 1007) is applied to the system
H20-tartaric acid. J. W. S.
O sm osis in s y s te m s co n sistin g of w ater and tartaric acid . II. F. A. H. S c h r e i n e m a k e r s and J- P. W e r r e (Proc. K. Akad. Wetensch. Amsterdam, 1932, 35, 162—170).—The behaviour of an osmotic system consisting of two solutions of tartaric acid of different concn., but one invariant, separated by a
membrane of pig’s bladder, is discussed with reference to experimental data. M. S. B.
Selective permeability and polarisation of membranes. ( M l l e . ) C h o u c r o n (Compt. rend., 1932, 194, 1661—1663; cf. A., 1928, 953).—Previous results obtained with gelatin are equally obtained with non-amphoteric membranes, e.g., agar, Or chlor
ide, A120 3 (calcined), or graphite. The statement that a porous membrane which separates solutions of different concns. of the same electrolyte is polarised only when the charge on the walls of the pores is of the same sign as that of the more mobile ion holds
generally. C. A. S.
Adsorption of gelatin by collodion membranes.
A. H. P a l m e r (J. Gen. Physiol., 1932, 15, 551—559).
—At 37°, with membranes of high permeability, max. adsorption of the gelatin occurs at much higher concn. of gelatin than with membranes of low per
meability. With the former, the max. is independent of p n from 3-8 to 4-8, but with the latter, adsorption is lower on both sides of the isoelectric point. The addition of NaCl neutralises the effect of p tt on the adsorption. The results are explained by previous work on the effect of p s and NaCl on the size of gelatin particles in solution. A. L .
Influence of electrolytes on specific heat of water. F. U r b a n (J. Physical Chom., 1932, 36, 1108—1122).—Sp. heats of 0-1 —2iff-BaCl2, -KC1, -K tartrates, -KOAc, and -KCNS and of 23/-NH4Cl and -KBr have been determined at 10—40°. The partial sp.
heats of H20 in 1M solutions of several electrolytes
•and in KC1 solutions of several concns. have been calc. The order in which the ions decrease the heat capacity of the solvent H20 is practically the same as the order in which they appear in the Hofmeister series. The diminution is explained by restriction of the motion of the H20 mols. by the ionic charges, and perhaps depolymerisation of the H„0.
•and in KC1 solutions of several concns. have been calc. The order in which the ions decrease the heat capacity of the solvent H20 is practically the same as the order in which they appear in the Hofmeister series. The diminution is explained by restriction of the motion of the H20 mols. by the ionic charges, and perhaps depolymerisation of the H„0.