THE TEMPERATURE COEFFICIENT OF THE DIFFUSION CONSTANT OF COPPER IN AQUEOUS SOLUTIONS OF SULPHURIC ACID CONTAINING COPPER SULPHATE

1944 ◽  
Vol 22b (1) ◽  
pp. 5-15 ◽  
Author(s):  
W. A. Patterson ◽  
J. T. Burt-Gerrans
Keyword(s):  
Aqueous Solutions ◽  
Temperature Coefficient ◽  
Sulphuric Acid ◽  
Copper Sulphate ◽  
Mathematical Theory ◽  
Diffusion Constant ◽  
Potential Curve ◽  
Viscosity Data

This paper presents values of the temperature coefficient of the diffusion constant of copper in aqueous solutions of sulphuric acid containing copper sulphate, for the range 10° to 25 °C. and four acid concentrations. The work is based on the Mathematical Theory of the Changes of Concentration at the Electrode, formulated by Rosebrugh and Miller. Evidence is presented supporting the choice of a new point on the oscillograph potential curve for the measurement of t. The values of K, thus obtained, at 18 °C. are in agreement with those of Cole and Gordon, who used the method of Northrop and Anson. The values of K at 10 °C. calculated from those at 25 °C. by means of viscosity data are in agreement with the values obtained by experiment.

scholarly journals Surface Thermodynamics, Viscosity, Activation Energy of N-Methyldiethanolamine Aqueous Solutions Promoted by Tetramethylammonium Arginate

Entropy ◽  
2020 ◽  
Vol 22 (12) ◽  
pp. 1337
Author(s):  
Xiangfeng Tian ◽  
Lemeng Wang ◽  
Pan Zhang ◽  
Dong Fu
Keyword(s):  
Activation Energy ◽  
Surface Tension ◽  
Diffusion Coefficient ◽  
Aqueous Solutions ◽  
Quantitative Relationship ◽  
Viscosity Data ◽  
Surface Thermodynamics ◽  
Surface Entropy ◽  
Operation Conditions ◽  
Surface Enthalpy

The surface tension and viscosity values of N-methyldiethanolamine (MDEA) aqueous solutions promoted by tetramethylammonium arginate ([N1111][Arg]) were measured and modeled. The experimental temperatures were 303.2 to 323.2 K. The mass fractions of MDEA (wMDEA) and [N1111][Arg] (w[N1111][Arg]) were 0.300 to 0.500 and 0.025 to 0.075, respectively. The measured surface tension and viscosity values were satisfactorily fitted to thermodynamic models. With the aid of experimentally viscosity data, the activation energy (Ea) and H2S diffusion coefficient (DH2S) of MDEA-[N1111][Arg] aqueous solution were deduced. The surface entropy and surface enthalpy of the solutions were calculated using the fitted model of the surface tension. The quantitative relationship between the calculated values (surface tension, surface entropy, surface enthalpy, viscosity, activation energy, and H2S diffusion coefficient) and the operation conditions (mass fraction and temperature) was demonstrated.

scholarly journals The influence of temperature on the absorption of water by seeds of hordeum vulgare in relation to the temperature coefficient of chemical change

1912 ◽  
Vol 85 (582) ◽  
pp. 546-553 ◽  
Keyword(s):  
Hordeum Vulgare ◽  
Aqueous Solutions ◽  
Temperature Coefficient ◽  
Chemical Change ◽  
Experimental Conditions ◽  
Influence Of Temperature ◽  
Suitable Medium ◽  
Influence Of Temperature On

Attention has previously been directed by one of us to the existence of a differential septum enclosing the seeds of Hordeum (barley). When the seeds are immersed in aqueous solutions of most electrolytes, and of many non-electrolytes, this covering behaves as a very efficient differential septum, water alone entering the seeds under the attractive influence of the finely granulated contents. The rate at which the water enters is considerably affected if substances are dissolved in it, being increased by some and diminished by others; it is also markedly dependent on the temperature of the water or solution in which the seeds are immersed. Variations of the rate at which water enters with alterations of the experimental conditions are presumably due mainly to changes in the water, and the seeds of Hordeum would thus appear to be a very suitable medium for the investigation of the nature of the changes produced in water by the presence of dissolved substances or by alterations of temperature.

Recovery of sulphuric acid from waste aqueous solutions containing arsenic by ion exchange

1997 ◽  
Vol 44 (1-2) ◽  
pp. 43-52 ◽  
Author(s):  
V. Nenov ◽  
N. Dimitrova ◽  
I. Dobrevsky
Keyword(s):  
Ion Exchange ◽  
Aqueous Solutions ◽  
Sulphuric Acid

scholarly journals The diffusion of oxygen and lactic acid through tissues

1928 ◽  
Vol 104 (728) ◽  
pp. 39-96 ◽  
Keyword(s):  
Lactic Acid ◽  
Aqueous Solutions ◽  
Nerve Fiber ◽  
Living Cell ◽  
Diffusion Constant ◽  
Fatigued Muscle ◽  
Single Nerve ◽  
Capillary Circulation ◽  
Determining Factor

The diffusion of dissolved substances through cells and tissues is a determining factor in many vital processes. The slowness of diffusion on the scale of ordinary sensible objects gives to the unaided imagination an imperfect realisation of its speed and importance in systems of the dimensions of the living cell. The diffusion constant k is expressed in terms of the number of unit quantities of substance which diffuse per minute across an area of 1 sq. cm. in a gradient of concentration per cm. of 1 unit quantity per c. c. For aqueous solutions of ordinary substances k is usually of the order of 2 to 10 times 10 -4 . The diffusion constant is of the dimensions L 2 T -1 , 2 in length, -1 in time. Expressing it in units of 1μ (0·0001 cm.) instead of 1 cm., and of 1σ (0·001 sec.) instead of minutes, k is of the order of unity, instead of multiple of 10 -4 . Thus the diffusion constant is a fairly large quantity for systems involving distances of the order of 1μ and times of the order of 1σ. A cylinder 1 cm. in diameter composed of material similar to frog's nerve, if suddenly placed in oxygen, would take 185 minutes to attain 90 per cent. of is full saturation with that gas. An actual nerve 0·7 mm. thick would take 54 seconds for the same stage of saturation to be reached. A single nerve fiber 7μ thick would take only 5·4 σ. Again, the rapidity of diffusion attainable in systems of small dimensions is the basis of the capillary circulation, and therewith of the whole design of the larger animals; and the rate at which diffusion an supply oxygen to a fatigued muscle for the removal of lactic acid is an important factor in determining the speed at which recovery can occur.

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