Heat capacity sodium chloride solution

For example, Marshall and Slusher (1966) made a detailed evaluation of the solubility of ealeium sulphate in aqueous sodium chloride solution, and suggested that variations in the ion solubility product could be described, for ionic strengths up to around 2 M at temperatures from 0 to 100 °C, by adding another term in an extended Debye Hiickel expression. Above 2 M and below 25 °C, however, further correction factors had to be applied, the abnormal behaviour being attributed to an increase in the complexity of the structure of water under these circumstances. Enthalpies and entropies of solution and specific heat capacity were also reported as functions of ionic strength and temperature. 

Gardner, W. L., Mitchell, R. E., and Cobble, J. W., 1969, The thermodynamic properties of high-temperature aqueous solutions. XI. Calorimetric determination of the stemdeird partial molar heat capacity and entropy of sodium chloride solutions from 100 to 200"C. J. Phys. Chem., 73 2025-32. 

Specific Enthalpies of Solution of Polymers and Copolymers, 13-42 to 69 Specific gravity see Density Specific heat see Heat capacity Specific volume see also Density mercury, 6-145 sodium chloride solutions, 6-9 water, 8-134... 

Dihydroxybenzaldehyde 5 9 0 A reaction flask (500-ml capacity) is fitted with an efficient stirrer, a reflux condenser, and a wide gas-inlet tube the end of the condenser is connected to, successively, a wash-bottle containing sulfuric acid, an empty safety flask, and a tube that passes over the surface of a sodium hydroxide solution. Resorcinol (20 g) and anhydrous ether (150-200 ml) are placed in the reaction flask, and anhydrous zinc cyanide (1.5 equivalents) is added. Then a rapid stream of dry gaseous hydrogen chloride is passed in. The zinc cyanide disappears as a milky mixture is formed and as the hydrogen chloride dissolves, the imide hydrochloride condensation product separates as a thick oil which solidifies in 10-30 min. The ether is usually saturated in 1.5 h, after which hydrogen chloride is passed in slowly for a further 0.5 h. Then the ether is decanted, water (100 ml) is added to the imide hydrochloride, and the solution is heated to the boiling point, filtered and allowed to cool. About half the aldehyde separates. After this has been collected the remainder of the aldehyde crystallizes in 10-15 h. The total yield is about 95 %, and the m.p. is 135-136° after recrystallization with charcoal from water. 

A three-necked flask (capacity 3 1) is fitted with a stirrer, dropping funnel (250-ml capacity) and reflux condenser carrying a calcium chloride tube. In it are placed dry toluene (250 ml) and sodium (23 g, 1 mole). This mixture is stirred and diethyl adipate (202 g, 1 mole) is dropped in over a period of about 2 h while the reaction mixture is heated in an oil-bath at 100-115°. This temperature is then maintained for a further 5 h. Dry toluene is added from time to time through the condenser so as to keep the mixture sufficiently fluid (750-1000 ml are needed for this purpose). After cooling, the product is poured slowly into 10% acetic acid (11), pre-cooled to 0° (ice-salt bath), and the toluene layer is separated and washed with, successively, water, cold 7 % sodium carbonate solution (twice), and water. The toluene is distilled off at atmospheric pressure and the residue is distilled in a vacuum. This affords a cyclic ester (115-127 g, 74-81 %), b.p. 83-88°/5 mm, 79-84°/3 mm. 

The solubilities of the scale-forming salts barium and strontium sulphates in aqueous solutions of sodium chloride have been reviewed by Raju and Atkinson (1988, 1989). Equations were proposed for the prediction of specific heat capacity, enthalpy and entropy of dissolution, etc., for all the species in the solubility equilibrium, and the major thermodynamic quantities and equilibrium constraints expressed as a function of temperature. Activity coefficients were calculated for given temperatures and NaCl concentrations and a computer program was used to predict the solubility of BaS04 up to 300 °C and SrS04 up to 125 °C. 

This series of papers contains an extensive array of correlated data on aqueous electrolyte solutions, much of It having been calculated using the system of equations given In paper I In this series. The contents of these papers have been summarized by Pitzer In a chapter in the book edited by Pytkowicz (see Item [123]). The data Include activity and osmotic coefficients, relative apparent molar enthalpies and heat capacities, excess Gibbs energies, entropies, heat capacities, volumes, and some equilibrium constants and enthalpies. Systems of Interest Include both binary solutions and multi-component mixtures. While most of the data pertain to 25 °C, the papers on sodium chloride, calcium chloride, and sodium carbonate cover the data at the temperatures for which experiments have been performed. Also see Items [48], [104], and [124]. 

Povodyreveta/. (1997) have developedasix-term Landau expansion crossover scaling model to describe the thermodynamic properties of near-critical binary mixtures, based on the same model for pure fluids and the isomorphism principle of the critical phenomena. The model describes densities and concentrations at vapor-liquid equflibrium and isochoric heat capacities in the one-phase region. The description shows crossover from asymptotic Ising-hke critical behavior to classical (mean-field) behavior. This model was applied to aqueous solutions of sodium chloride. 

Oxalyl-acetic ester (20 gms.) is mixed with mono-bromacetic ester (17 gms.) in a flask of 300 c.c, capacity, fitted with an air-condenser. Enough zinc turnings to cover the end of a spatula are added and the mixture becomes brown, while the temperature quickly reaches 50° and the zinc dissolves. Addition of a second portion of zinc is attended by boiling and the reaction is moderated by cooling the metal is added in excess, and the mixture is then heated on the water-bath for a short time. After cooling, the mixture is treated with cold dilute sulphuric acid and ether, well shaken to get a clear solution, and the ethereal layer removed, washed with dilute sodium carbonate and dried over calcium chloride. The ether is next distilled and the remaining oil fractionated under reduced pressure most of it passes over below 200° at 35 mm. That portion taken as citric ester (b.p, 212°—216°) is hydrolysed... 

Preparation of carbon monoxide from formic acid 50e A round-bottomed flask (capacity 1 1) is fitted by ground-glass joints with a dropping funnel and a gas-outlet tube, filled two-thirds full with concentrated phosphoric acid, and heated in a water-bath to 80° then formic acid is dropped in slowly. For removal of impurities (carbon dioxide, air, acid vapors, water vapor), the carbon monoxide evolved is passed successively through 50% potassium hydroxide solution and an alkaline solution of sodium dithionate (25 g of dithionate in 125 ml of water containing also 20 ml of 70% potassium hydroxide solution) and over potassium hydroxide, calcium chloride, and phosphoric oxide. 

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