Binary systems containing either butyl or ethyl alcohol were investigated. Deviation from

Raoult’s law is very considerable. The results do not conform to Langmuir’s theory. The orientation of the alcohol molecules relative to one another appears to bo more important in determining the behaviour of the system than their orientation relative to the molecules of the other component or the orientation of the molecules of the other component relative to one another. The deviations from Langmuir’s theory are qualitatively explained in terms of the forces acting between the molecular dipoles.

S. K . Tw e e d y.

M eth ods of d eterm in in g h eats of vap orisation of liq u id m ix tu re s. V. Ki r e j e v (Z. Physik, 1929, 57, 403—410).—The heat of vaporisation of liquid mixtures may be derived from the heats of vaporis­

ation of the pure components and the heat of dis­

solution, and also from the corresponding vapour- pressure data for the mixture. The theories of these methods as well as the definitions of the quantities used have been treated differently by different observers, leading to contradictory results. The results obtained by both the indirect methods are compared with the direct experimental results.

The values derived from vapour-pressure data show large deviations. The magnitude of the heat of vaporisation of single components of a mixture may bo very different from that of the components in the

pure state. A. J. Me e.

V aporisation of b in ary m ix tu re s. I. M ethod of d eterm in in g h eats of vap orisation of pure liq u id s and solu tion s. M. S. Vr e v s k i (Z. physikal.

Chem., 1929, 144, 244—252).—A new method for determining heats of vaporisation at constant temper­

ature has been worked out and applied to water and a solution of sulphuric acid. A knowledge of this constant is essential to the understanding of dis­

solution processes from an energetic point of view.

F. L. Us h e r.

V iscosity and m . p. of th e s y ste m ethylen ed i- am in e-w ater. M. S. El g o r t (J. Russ. Phys. Chem.

Soc., 1929, 61, 947—959).—A study of the viscosity

isotherms and m. p. of the above system shows the existence of ethylmediamine diliydrate, m. p. —1 0°.

The eutectic point is —53° at 83-2 mol.-% H20 . R. Tr u s z k o w s k i.

M . p. of m ix tu r e s of cyciohexane and benzene.

I. Se t o (Bull. Centr. Res. Inst. S . Manchuria Rly.

Co., 1928, 13 , 123— 125).—Maximal expansion was observed at 55-56% of cj/cZohexane. The m.-p. curve shows the existence at -4 1 -9 ° of a eutectic containing 74-44% of cycZohexanc. Ch e m ic a l Ab s t r a c t s.

R efraction of alco h o l-w a ter m ix tu re s. N.

Sc h o o r l (Pharm. Weekblad, 1929, 6 6, 905—920).—

The data recorded in the literature for the refractive indices of absolute alcohol and of alcohol-water mixtures are found to be unsatisfactory for the analysis of mixtures. Tables are given of data obtained with the Eykman and Pulfrich-Zeiss refractometers. For analytical purposes the mixture should contain about 30 wt.-% of alcohol, as in this region the refractive index alters most rapidly with the

composition. S . I. Le v y.

X -R ay in v estig a tio n of p a lla d iu m -s ilv e r - h yd rogen alloy. I. Á. Os a w a (J. Study Met., 1928, 5, 443—454).— Palladium and silver both have a face-centred cubic lattice with lattice constant 4-069 and 3-86—3-874 Á., respectively, and form a solid solution for all ranges of composition. Satur­

ation of palladium with hydrogen increases the lattice constant by 3-6—3-87%. Palladium-silver alloys absorb hydrogen well. The expansion coefficient increases from an alloy containing 30% Pd to a maximum at 100% Pd. Ch e m i c a l Ab s t r a c t s.

E la stic co n sta n ts, la ttice co n stan ts, and d en sitie s of m e ta llic so lid solu tion s. Z. Ni s h i- y a m a (J. Study Met., 1929, 6, 17— 41).—Binary solid solutions of nickel, silicon, aluminium, cobalt, vanadium, tungsten, chromium, and manganese with iron; of aluminium, tin, zinc, manganese, and nickel with copper; of iron and copper with nickel; and of zinc and manganese with aluminium were studied.

Ch e m ic a l Ab s t r a c t s.

S p ecia l p ro p erties of eu tectic and eutectoid allo y s in b in ary m e ta llic sy ste m s. P. J. Sa l d au (J. Russ. Phys. Chem. Soc., 1929, 61, 837—882).—

Reheated eutectic alloys of the pairs tin-zinc, tin - antimony, tin-zinc, gold-zinc, and gold-cadmium, as well as reheated eutectoid carbon steel, show greater hardness and a smaller electrical conductivity and temperature coefficient than alloys of different com­

position. It follows that the physical and mechanical constants of reheated eutectic alloys do not he on the curves obtained for mechanical mixtures which would be obtained by the fusion together of the given components of a system. Eutectic and eutectoid alloys show either a maximum or a minimum.

value. This relation persists at all temperatures below the m. p. in the case of eutectic alloys or below the transition point in the case of eutectoid alloys, and is restored on cooling should the alloys have been heated above these temperatures. The presence in excess of one of the eutectic phases is essential for the process of coalescence in reheated eutectic alloys.

R. Tr u s z k o w s k i.

GENERAL, PH Y SICAL, AN D INORGANIC CHEM ISTRY. 1375 S y ste m s form ed b y certain tetrah alid es. P. A.

Bo n d and W. R. St e p h e n s (J. Amer. Chem. Soc., 1929, 51, 2910—2922).—The miscibility of the tetra­

chlorides of titanium and of silicon with liquid sulphur dioxide has been examined. The results accord with theory as regards polarity etc. The solubility of zirconium tetrachloride in liquid sulphur dioxide between 0° and 2 0° was determined by a method specially adapted for measuring solubility in highly volatile solvents; the results agree with the principles governing solubihty where there is a large difference of polarity. The compound ZrCl4,S 02 was isolated in the form of colourless plates, stable at and below 0°.

S. K. Tw e e d y.

S o lu b ility of ethylene glycol. H . M . Tr i m b l e

and G. E. Fr a z e r (Ind. Eng. Chem., 1929, 21, 1063—1065).—Ternary systems of ethylene glycol and acetone with xylene (25°), toluene (27°), chloro- benzene (23°), bromobenzene (25°), nitrobenzene (22°), and benzene (27°), and of glycol and alcohol with xylene (26°), toluene (25°), benzene (25°), and nitrobenzene (29°), have been investigated at the temperatures indicated. In each case a single binodal curve is obtained. Tie-lines are shown for all the systems containing acetone.

C. W. Gi b b y.

S o lu b ility of ether in concentrated solu tion s of m in era l acid s. C. Ma r i e and G. Le j e u n e

(Monatsh., 1929, 53 and 54, 69—72).—The solubility curves for ether in various concentrations (2— IliV) of perchloric, hydrochloric, sulphuric, and phosphoric acids have been determined at 18° and 25°. The solubility is greatest in perchloric acid; a maximum is shown at 6-5—1 M . In general, an increase in the concentration of the acid of 1 mol. per litre (at the concentrations where solubility is of a measurable order) causes an increase of the solubility of ether by 20, 1-8, 2-25, and 7-5 mols., respectively, for the

above order. H. Bu r t o n.

L im it of so lu b ility of copper in reversib le ferro-n ick els. P. Ch e v e n a r d (Compt. rend., 1929, 189, 576—578).— Dilatometric observations show that ternary austenite is formed in the presence of small amounts of copper. A second constituent rich in copper appears in the austenite when the pro­

portion of copper is increased, but this disappears on tempering. The logarithmic contraction-time curve (cf. A., 1923, ii, 166) associated with the pre­

cipitation of Mg2Si from hyper-tempered aluminium- magnesium-silicon alloys (isothermal recovery) has

been confirmed. J. Gr a n t.

S o lu b ility of n itric oxid e in carbon te tra ­ chloride, benzene, and n itrobenzene. A.

Kl e m e n c and E. Sp i t z e r- Ne u m a n n (Monatsh., 1929, 53 and 54,413—419).—Determination of the Ostwald solubihty coefficients for nitric oxide in benzene and carbon tetrachloride at 8-8—34-6° shows that these rise with the temperature for each solvent. With nitrobenzene at 20—90° the coefficient is the same at all temperatures. The free energy of the dis­

solution process decreases with rising temperature.

Nitric oxide dissolves in benzene and carbon tetra­

chloride with a small negative heat of dissolution.

H . Bu r t o n.

S o lu b ility of so d iu m th iocyan ate in w a ter and in o rgan ic solv en ts. 0 . L . Hu g h e s and T. H . Me a d (J.C.S., 1929, 2282—2284).—The solubility of sodium thiocyanate in water has been measured between 10-7° and 101-4°; a hydrate NaCNS,H20 is formed below 30-4°. The solubilities have also been determined in methyl alcohol from 15-8° to 52-3°, in ethyl alcohol from 18-8° to 70-9°, and in acetone from 18-8° to 56° (compound NaCNS,COMe2).

C W. Gi b b y.

S olu b ility of so d iu m ferrocyanide in w a ter b etw een 0° and 104°. J. A. N. Fr i e n d, J. E.

To w n l e y, and R. H. Va l l a n c e (J.C.S.,1929, 2326—

2330).—The solubility of sodium ferrocyanide in water has been determined by a gravimetric method.

Above 65° the results diverge from those of previous workers (cf. Conroy, A., 1899, i, 2; Farrow, A., 1926,

236). * C. W. Gi b b y.

H yd rates of lith iu m su lp h ate and th eir so lu b ­ ility in w a ter b etw een —16° and 103°, J. A. N.

Fr i e n d (J.C.S., 1929, 2330—2333).—The solubility of lithium sulphate in water has been determined between —16° and 103°. A break in the curve was found at — 8°. A dihydrate is possibly formed at lower

temperatures. C. W. Gi b b y.

S o lu b ility of ben zidin e su lp h ate and benzidine h ydroch loride in h ydroch loric acid solu tio n s.

W. B . Me l d r u m and 1. G . Ne w l i n (Ind. Eng. Chem.

[Anal.], 1929, 1, 231).—The solubility of benzidine sulphate in hydrochloric acid at 25° increases rapidly with the acidity, and attains a maximum of about 1-93 g. per litre in 3-5iST-acid, thereafter decreasing slowly. The solubility of benzidine hydrochloride under similar conditions decreases rapidly from 5-34 g. per litre in pure water to 1-24 g. per litre in 5-6/V-acid, remaining constant at this value for higher concentrations of acid up to 102\7.

H . F . Ha r w o o d.

C onnexion b etw een velo city of d isso lu tio n and so lu b ility . G eneral equation for so lu b ility. I.

W. Ja c e k (Rocz. Chem., 1929, 9, 472—492).—If k is the thickness of the layer of saturated solution which would be obtained by the concentration of the dilute solution formed in unit time by the immersion of the solute, the surface of which is taken as constant, and p' the thickness of the layer of solute dissolved in unit time by the pure solvent, then p'S/kA=C', where S is the density of the solute, A that of the saturated solution, and c' the solubility expressed per unit weight of saturated solution. A further expression, s=p'S/58', is derived, in which s is the solubility per unit weight of solvent, S' the density of the solvent, and i; is the thickness of the layer of pure solvent corresponding with p'. The value of p' is determined for sylvine, sodium chloride, alabaster, potassium sulphate and dichromate, alum, tartaric acid, and sucrose, for temperatures between 0° and 50°. The relation between p' and temperature, T, is given by p'8= e ~ Jll/7'+•s,, where the constant B y depends on the rate of stirring. A general equation for the solu­

bility is given by s =e -<-,,i ~ o j . The terms (A t —A 2), (B j—B„), ( C ^ C ^ , and (G1—G2) depend on the heat of dissolution of the given solute and on the nature of both components of the solution,

1376 B R IT ISH CHEMICAL ABSTRACTS.— A .

and may have positive, negative, or zero values, and the differences observed between the solubility curves of various substances are due to the differential nature of these terms. R. Tr u s z k o w s i u.

A d sorp tion of air and w a te r vapour on rock- sa lt su rfaces. J. H. F r a z e r (Physical Rev., 1929, [ii], 34, 644—648).— By a method previously used (cf. this vol., 503) the adsorption of air on rock-salt surfaces has been measured at various temperatures, and the temperature at which complete outgassing occurs determined. The thickness and approximate speed of formation of the film are estimated. Exposure to water vapour has no permanent effect on the surface so long as the partial pressure of the water vapour is less than that of the saturated solution at the same temperature. This is true only of cleavage Surfaces; polished surfaces are less stable against the action of water vapour. N. M. B l i g h .

S orp tion of vap ours fro m circu latin g g a s by solid a b sorb en ts and th e adaptation of activated charcoal and silic a g e l to th e d eterm in ation of sm a ll q u an tities of vap ours in exh aled b reath.

W. Po n n d o r f and H. W. K n i p p i n g (Beitr. Klin.

Tuberk., 1928, 6 8, 751—806; Chem. Zentr., 1929, i, 2904).—The principle of the process is discussed, and curves illustrate the effect of the form of the absorbent layer, the temperature, and the pressure. Silica gel is preferable for the absorption of water and active charcoal for that of acetone and other organic sub­

stances. Acetone can be quantitatively absorbed from large volumes of moist air.

A. A. El d r i d g e.

T em p eratu re coefficient of th e satu ration m a x im u m in g a seo u s adsorption. F. J. W i l k i n s

and A. F. H. W a r d (Z. physikal. Chem., 1929, 1 4 4 , 259—268).—Theoretical. The temperature vari­

ation of the value of the saturation maximum expected from Langmuir’s and other theories is discussed.

The basis of the alteration is to be sought, not in a change of the adsorbing surface, as Zeise supposes, but rather in the adsorbed gas layer. From the conception of lateral diffusion of the adsorbed uni- molecular gas layer, the saturation pressure is found to be independent of the temperature, whilst the temper­

ature coefficient of the adsorption maximum is equal to the coefficient of expansion of a gas at constant pressure. This conclusion is supported by the available experimental data. F. L. U s h e r .

L inear ad sorp tion. R. S. Br a d l e y (Phil. Mag., 1929, [vii], 8,202—204).—The thermodynamic surface activity is given by the expression R T l o g a t = F '—F'0—R T log F-\-BF, where a, is the surface activity, B is a constant and the standard state for F', the free energy per g.-mol. in the surface being defined by the limits F ‘— >F'0 when A —B /A — >-1, -4— y R T /F , and a,— >F, where A is the area per g.-mol. Applying this to a two-dimensional gas the Langmuir isotherm becomes c o n sta n t/p = l/s—

constant, where p is the pressure and s is the surface concentration, the substance distributing itself between the two regions according to the distribution law p /{s/ (1—S B )}= constant, S /(1 —SB) being the effective surface concentration. Similar application to adsorption at a line gives R T Jog tti—R T log

RTL'-\-RTB^L', where at is the linear activity and L' is the effective linear concentration=j6/ ( l — LBl), where L is the linear concentration. The approximate distribution law between a line and a surface then becomes L '/S '—constant=eJiVR7’, where S '—

S /( 1 —SB) and AF0 is the free energy increase for tho change line— »-surface in the standard states.

A. E. Mi t c h e l l.

H eat of ad sorp tion of g a s e s b y so lid s. K. F.

H e r z f e l d (J. Amer. Chem. Soc., 1929, 5 1 , 2608—

2621).—Theoretical. On the assumption that the adsorbing forces are purely of electrical nature, the adsorption of a gas without permanent dipoles on the surface of a heteropolar salt is investigated mathematically and it is shown that the positive or negative increase in the heat of adsorption with the amount adsorbed can be explained by the interaction of the dipoles set up in neighbouring molecules by the adsorbing forces. The association of a large free energy change during adsorption with a small total energy change is best explained (but not with com­

plete satisfaction) by assuming that the adsorbed molecules cohere together into groups. The extent of the difference between the amounts of two gases (having the same heat of adsorption) adsorbed on the same adsorbent under the same external pressure is discussed briefly. S. K. T w e e d y .

M ixed ad sorb en ts. N. S c h i l o v , M . D u b i n i n ,

and S. T o p o r o v (Kolloid-Z., 1929, 49, 120— 126).—

A method for the preparation of an intimate mixture of silica and wood charcoal for adsorption purposes is described. This mixed adsorbent is more active than wood charcoal alone in the adsorption of ammonia, chlorine, steam, and benzene vapour and in the adsorption of iodine from solution in water, alcohol, or benzene. The maximum activity is attained when the adsorbent contains 60—70% of carbon. Although silica gel adsorbs iodine negatively, it increases the adsorption by carbon. Coarse mixtures of silica and wood charcoal have less adsorbent capacity than wood charcoal alone.

E. S . He d g e s,

A d sorp tion v elocity of w a ter and benzene vapours. H. I s o b e and S. M o r i (Bull. Inst. Phys.

Chem. Res. Tokyo, 1929, 8, 801— 804).—Activated charcoal adsorbs more benzene than water from air saturated with both substances, whereas for acidic clay the reverse is true; with both adsorbents the adsorption of benzene is more rapid than that of water. Density measurements indicate that activated charcoal possesses a greater surface than non­

activated charcoal. H. F. G i l l b e .

A d sorp tion and gas-friction . C. D r u c k e r (Z.

Elektroehem, 1929, 3 5 , 640—644).—Expressions are obtained by which the coefficient of friction of mixtures of gases, e.g., helium and hydrogen, carbon dioxide and hydrogen, hydrogen chloride and hydro­

gen, can be calculated with fair accuracy. With the help of these formula, it is possible to determine the adsorption of the gases by the glass walls of the containing vessel. H . T . S. B r i t t o n .

P ro c ess of ad sorp tion. H. K a l b e r e r , H.

M a r k , and C. S c h u s t e r (Z. Elektroehem., 1929, 3 5 ,

600—602).—The adsorbing surfaces of silica gel and

G ENERAL, PHY SICAL, A N D INORGANIC CHEM ISTRY. 1377 aluminium oxide have been calculated from an

expression involving the heat of adsorption, the thickness of the adsorbed layer, and the volume occupied by the adsorbed gas. The different values obtained for the surface of an adsorbent when different gases are used is attributed to differences in the adsorption potential which the active places in the surface have for the particular gases (see Kalberer and Schuster, this vol., 757). The depend­

ence of the volume of adsorbed gas on the temperature is also discussed. H. T. S. Br i t t o n.

A d sorp tion of co m p lex p latin u m com pou n ds b y carbon. I. I. Sh u k o v and 0 . P. Sc h i f u l i n a

(Kolloid-Z., 1929, 49, 126— 133).—The adsorption of a number of complex platinum compounds by wood charcoal has been studied. The compounds were decomposed on adsorption and the adsorbability depends on the electronic configuration of the com­

pound, no relation being found between adsorbability and solubility. The adsorbability is influenced by isomerism only so long as a change in electrical configuration is involved. Of the compounds examined, the non-electrolytes were adsorbed more strongly than the electrolytes. Optically active complex platinum compounds cannot be resolved into their isomerides by adsorption on charcoal.

E. S. He d g e s.

P recip ita tio n and ad sorp tion of s m a ll q uan tities of su b stan ces. III. T he ad sorp tion law , ap p lication s, re su lts, and con clu sion s.

0 . Ha h n and L. Im r e (Z. physikal. Chem., 1929,144, 161—186; cf. A., 1926, 1092).—The authors dis­

tinguish between the co-precipitation of small amounts of a substance with a bulky precipitate and the adsorption of the substance by the precipitate, and the two laws previously put forward are restated and confirmed by new data. In the present work the adsorption of hydrolysing and non-hydrolysing cations by two types of lattice, polar and non-polar, is con­

sidered. The polar lattices studied were those of the silver halides, the non-polar those of the mercurous halides. The adsorbed substances were the short­

lived radio-elements thorium-5, thorium-C, and polonium (hydrolysing ions), radium and thorium-C"' (non-hydrolysing), chosen for convenience in detecting small amounts, but the results are generally applicable.

The difference between the behaviour of non­

hydrolysing and hydrolysing cations is striking, inasmuch as the latter show “ colloid adsorption,” and an excess of the precipitating anion is not necessary for considerable adsorption to occur. Appreciable adsorption occurs only under special conditions on non-polar precipitates such as the mercurous halides, since they lose their charge much more readily than the analogous silver compounds, but under these conditions Hahn’s adsorption law is followed. The results of ionic and colloid adsorption on polar and non-polar lattices are summarised. The earlier results of Fajans are in agreement with the authors’ views on adsorption processes. A possible extension of the adsorption law to readily soluble but weakly dis­

sociating compounds is indicated. F. L. Us h e r.

Influence of adsorbed io n s on th e ab sorp tion sp ectru m of m e ta l h alid es. K . Fa j a n s a n d

G. Ka r a g u n i s (Z. physikal Chem., 1929, B , 5, 385—

405).—Measurements with silver iodide analogous to those previously conducted with silver bromide (this vol., 625) show that adsorbed silver ions produce up to 40% increase in the intensity of the band with its maximum at 4200 A., without, however, influencing the position of the maximum. Adsorbed iodine ions produce a decrease of absorption on the long wave­

length side of the maximum. These results are in accordance with the colour variations exhibited by the iodide when precipitated in presence of an excess of iodide or of silver ion. Mercuric iodide emulsions show a general decrease of absorption when treated with a solution of a mercuric salt or of a soluble iodide on account of the formation of non-absorbing complex ions. The energy quantum of the primary process of the photochemical decomposition of silver iodide is not altered by the presence of adsorbed silver ions, but the number of elementary processes is increased.

H . F. Gi l l b e.

L yosorption. Wo. Os t w a l d and W. Ha l l e r

L yosorption. Wo. Os t w a l d and W. Ha l l e r