Inorganic Acid Solutions Research Articles

Proton Transfer Kinetics in Medium-strong Inorganic Acids

A method of obtaining relative and absolute rate constants for proton transfer equilibria is described. It is suitable for equilibria of the type[Formula: see text]in dilute (< 0.1 M) solutions of medium strong inorganic acids. To obtain absolute values of kd, kr it is necessary to know the value of ΔV0 for the equilibrium. Ultrasonic absorption data for aqueous solutions of H3PO4, H3AsO4, and H2SO4 at 20, 10, and 0 °C are presented together with data at 20 °C for H3PO3, H2SeO3, HIO4, NaHSO4, KHSO4, and NH4HSO4. From analysis of the concentration dependence of the excess absorption, values of Ka are calculated for these acids, and values of kd, kr for those where ΔV0 is available. The Ka obtained are in reasonable agreement with literature values except for HIO4 and H2SeO4. The absolute values of kr for H3PO4, H3AsO4, and HSO4− indicate that the diffusion controlled recombination process postulated is complete when the ions are about 15 Å from each other.

有機酸溶液中におけるステンレス鋼の腐食に関する研究 (第6報)

Polarization and weight loss tests on iron-chromium alloys were conducted in saturated monocarboxylic acid solutions. The results obtained were as follows:(1) The critical current density and passive current density decreased as increasing the chromium content in alloys.(2) Alloys of high chromium content began to dissolve in the hexavalent condition of chromium at a potential of about Eh=1.2V in the same manner as in inorganic acid solutions.(3) The corrosion rate of alloys containing up to 18% Cr was greater than that of pure iron in formic and acetic acid solutions. But, in propionic and butyric acid solutions, the corrosion rate decreased gradually as chromium content increased.(4) The corrosion rate decreased as increasing the carbon content in saturated monocarboxylic acids.

The Heterogeneous Reaction of Recrystallised Precipitated Gibbsite Powder with Aqueous Inorganic Acid Solutions; Kinetics and Mechanism

The Heterogeneous Reaction of Recrystallised Precipitated Gibbsite Powder with Aqueous Inorganic Acid Solutions; Kinetics and Mechanism

The Dissolution of Olivine in Aqueous Solutions of Inorganic Acids

Abstract The dissolution of olivine was studied in aqueous solutions of inorganic acids at temperatures of 35, 50, and 65°C in order to obtain basic information about the alteration and leaching processes in acid hot spring regions. The rates of dissolution have been determined by measuring the change in the concentrations of silica, magnesium, and the total iron leached in the solutions as a function of the time. Olivine dissolved in stirred aqueous solutions of 0.05–2n perchloric, hydrochloric, and sulphuric acids without any selective dissolution of components in the mineral. The rate at which olivine dissolved was found to be two-thirds of the reaction order with respect to the sample-powder (10–20 μ in diameter) weight (i.e., first order with respect to the surface area) and to decrease in the order of H2SO4>>HCl>HClO4. HSO4− enchanced the rate remarkably. The complexing affinity of the anions did not play an important part in the reaction with olivine powder.

Reaction mechanism for the acid-catalyzed hydrolysis of saccharose

1. A polarimetric study was made of the reaction for the hydrolysis of saccharose in inorganic acid solutions. 2. The A-1 mechanism, on the assumption that saccharose is a base of the type of a Hammett indicator, does not describe the experimental data.

Thin-layer chromatographic and electrophoretic behaviour of primary aromatic amines on weak ion exchangers

The authors have studied extensively the thin-layer chromatographic and electrophoretic behaviour of primary aromatic amines on weak ion exchangers such as alginic acid and carboxymethylcellulose. The eluents were solutions of organic and inorganic acids, water, buffer solutions and aqueous organic solvents. The R F values were correlated with the acidity and basicity of many amines.

A study of the rate of inversion of sucrose in aqueous solutions of some strongly dissociated acids: primary kinetic salt effects and acidity constants

The rate of inversion of sucrose has been studied for dilute aqueous solutions of several strong inorganic acids prepared by ion exchange from their alkali-metal salts. The acids were chloric, thiocyanic, methylsulphuric, methanesulphonic, and dithionic. Similar measurements have also been made with dilute solutions of three acids of intermediate strength, viz. sulphamic, hypophosphorous, and trichloroacetic, and a reliable value of the acidity constant Ka has been determined in each case. For an electrolyte of intermediate strength, the impossibility of fixing Ka independent of other parameters from a single type of measurement is emphasized. Previous determinations of the second dissociation constant of sulphuric acid from e.m.f. and kinetic measurements are compared, and the single set of parameter values which gives the best fit of all the data is determined.

The heterogeneous reaction of Gibbsite powder with aqueous inorganic acid solutions; kinetics and mechanism

Gibbsite powders (surface area 0·4–1·2 m.2/g.) react with well stirred aqueous inorganic acid solutions (0·5–10 g.-ion/l.) according to a four-thirds reaction order with respect to powder weight (i.e., second order in powder surface area). The rate constants (in excess of acid) vary linearly with acid concentration and with the function a±aw2; for perchloric acid (at a±= 1, aw= 1), the rate constants k1 for Gibbsite D at unit proton activity, are at 35°, 0·071; at 50°, 0·115; and at 65°, 0·195 g.–1(m.2/g.)–2 hr.–1. Hydrochloric acid solutions dissolve Gibbsite about three times faster than perchlorc acid solutions of equal concentration; chloride ions alone do not (complex Al and) dissolve Gibbsite. Hydrogen bisulphate ion solutions dissolve Gibbsite even in the absence of excess of hydrogen ion and also enhance hydrogen-ion reactivity. Overall, sulphuric acid solutions dissolve Gibbsite 15–30 times faster than perchloric acid of equal molar concentration. The energy of activation for the reactions (at 35–65°) varies from 10,600 to 12,500 cal./mole: the enhanced rates with the complexing ions correspond to increase in pre-exponential terms. The rate constants vary slightly with the particle size of the powder. The rate-determining step appears to be a bimolecular reaction between highly hydrated hydrogen ion adsorbed on the powder surface and adjacent reactive Al–OH sites.

沸騰無機酸中におけるTiの不働態と不働態表面の酸化膜について

沸騰無機酸中におけるTiの不働態と不働態表面の酸化膜について

A Theory of Surface Tension of Aqueous Solutions of Inorganic Acids

A Theory of Surface Tension of Aqueous Solutions of Inorganic Acids

The swelling of fish skins in solutions of inorganic and organic acids

In experiments carried out partly in the laboratory and partly in breweries, it was noticed that when the method commonly used for the preparation of clarifying medium from isinglass was applied to fish skins, the latter were found to contain a high percentage of collagen, but they showed only slight swelling and very little gelatin diffused from them. When the organic acid used was varied, it was noticed that the behaviour of the skins changed considerably. In extreme cases shrinkage replaced swelling. The constitution of gelatin obtained from fish skins is different from that obtained from mammalian skins, and the great difference in the behaviour of gelatin according to whether it is obtained from fish skins or from mammalian skins may, with certainty, be attributed to this difference in chemical composition. No attempt is made in this paper to describe at length the chemical constitution of fish gelatin. We limit ourselves merely to a suggestion as to how its chemical constitution may influence the action of the reagents used to bring about swelling. Gelatin from fish skins is also likely to differ chemically from that extracted from the swim bladder. Though there is no exact knowledge of the chemistry of the two gelatins, the fact that the swimming bladder develops from the meso-blast, whilst the skin develops from the epi-blast, justifies one in looking for profound chemical differences. In this case also, the difference in chemical constitution is probably the cause of the difference in the behaviour of the respective materials to swelling agents. One specific difference between material of mammalian and material of fish origin may be noted here. Gelatin from calf skin, and the skin itself will absorb considerable quantities of water and yet retain the original structure. Fish skins, however, and the gelatin extracted from them, and isinglass absorb only a little water, up to a certain definite point. When this point is passed, there is disruption accompanied by considerable diffusion of nitrogenous products into the aqueous phase.

Societies and Academies

LONDON. Royal Society, November 25.-Sir William Crookes, president, in the chair.-M. i-lack, O. W. Griffith, and L. Hill: The measurement of the rate of heat loss at body temperature by convection, radiation, and evaporation. An investigation of the rate of cooling of a surface at body temperature (i) dry, (2) wet, under varying conditions of atmosphere, with the view of elucidating the effects of climate, and of heating and ventilation of rooms on health and comfort. A large-bulbed spirit thermometer is employed of standard pattern-the Kata thermometer; methods of calibrating have been worked out, and a factor determined for each, so that the rate of cooling can be expressed in milli-calories per sq. cm. per sec. Some thousands of observations have been made in still air under varying conditions, and the cooling curves plotted; the theory of cooling detailed is the work of the late O. W. Griffith. Experimental results, independently obtained, agree with theory.-E. W. A. Walker: The growth of the body in man. The relationship between the body-weight and the body-length (stem-length). Observations have been made on infants, children, and young persons up to early adult age in order to determine whether any definite relationship could be shown to exist between the body-weight and the body-length. By the term body-length is meant the stem-length measured from the top of the head to the line joining the ischial tuberosities. This measurement corresponds to the body-length in animals, and was chosen in order that results obtained for man might be brought into comparison with those for other animals. The author finds that throughout the period of growth stem-length in man can correctly be expressed as a function of body-weight, and conforms to the formula, l = k.wf-; where I is stem-length, w weight, fe a constant, and n a power of approximate value. For the male the value of n (to two places of decimals) is 0-33, for the female it is 0-32. If the stem-length differ by as much as 16-5 per cent, from the value calculated from the body-weight by means of the appropriate formula, the individual may be regarded as abnormal.-Prof. A. J. Brown and F. Tinker: The rate of absorption of various phenolic solutions by seeds of Hordeum vulgare, and the factors governing the rate of diffusion of aqueous solutions across semi-permeable membranes. It has been pointed out previously that the seeds of Hordeum (barley) are enclosed by a membrane which exhibits the exceptional property of differential permeability. When the dry seeds are immersed in aqueous solutions of most inorganic acids and salts, sugars, etc., water alone passes through their containing membrane; with other classes of solutes, however, such as the phenols, fatty acids, and monohydric alcohols, the solute enters the seeds together with water.. In order to learn something of the physical properties which presumably govern the exhibition of differential permeability (only recognised to a marked extent with living protoplasm and with the coverings of certain seeds), experiments have been made with a series of closely-related organic solutes, viz., phenol, catechol, resorcinol, quinol, and pyrogallol, all of which enter the seeds of Hordeum when in aqueous solution. Experiment appears to justify the conclusion that when the temperatures, osmotic pressures, vapour pressures, and viscosities of a series of solutions of permeable solutes are equal, their rates of diffusion across the seed-membrane are inversely proportional to their surface tensions.-F. Kidd: The controlling influence of carbonic dioxide. III.-The retarding effect of carbon dioxide on respiration. Researches previously described led to the conclusion that the resting stage of the moist seed is primarily a phase of auto-narcosis induced by tissue CO,. Inhibition of germination by CO2 was demonstrated in the laboratory and in the field under a wide range of conditions. Inter alia, it was shown that the inhibitory value of a given carbon dioxide pressure diminishes with a rise of oxygen pressure and also with a rise of temprature. These researches have now been carried further to determine if possible the mechanism CO2-narcosis. The present paper deals with the effect of CO2 upon the respiratory function. The outstanding result shown is that CO2 causes a marked retardation of respiration.

The rate of absorption of various phenolic solutions by seeds of Hordeum vulgare , and the factors governing the rate of diffusion of aqueous solutions across semipermeable membranes

It has been pointed out previously that the seeds of Hordeum (barley) are enclosed by a membrane which exhibits the exceptional property of differential permeability, and that use may be made of this property of the seeds for the purpose of investigating some of the obscure phenomena associated with osmosis.† When the dry seeds are immersed in aqueous solutions of most inorganic acids and salts, sugars, etc., water only passes through the containing membrane and moistens their starchy contents; with other classes of solutes, however, such as the phenols, fatty acids, and monohydric alcohols, the solute enters the seeds together with water. A dry seed of Hordeum may be regarded, therefore, as a diffusion system consisting of a mass of solid material capable of absorbing moisture, enclosed within a differentially permeable membrane. In the presence of those solutes which do not enter the seed-diffusion-system along with the solvent the action of its membrane is comparable to that of a copper-ferrocyanide membrane in contact with sugar solution. On the other hand, in the presence of those solutes which do enter the seed-diffusion-system together with the water, its membrane evidences a property of selective permeability only recognised to any extent with living protoplasm, and with the coverings of certain seeds.

On the refractive indices and densities of normal and semi-normal aqueous solutions of hydrogen chloride and the chlorides of the alkalis

A very large number of observations have been made of the refractive indices and densities of aqueous solutions of inorganic salts and acids: in England, more especially, by Dr. J. H. Gladstone, who in a paper in the ‘Philosophical Transactions’ for 1870, gave the values he had obtained for the refractive indices and densities of some 160 salts and acids; and in a series of papers published subsequently in the 'Journal of the Chemical Society,’ has given the results of further observations. Most, however, of these determinations have been made with solutions of different strengths, and at different temperatures, and, therefore, I venture to bring before the Royal Society an account of some observations I have made of the refractive indices and densities of normal and semi-normal aqueous solutions of hydrogen chloride, and the chlorides of the alkalis at a uniform temperature of 18°.