Dilute Potassium Chloride Research Articles

Development of an In-Field Method for the Detection of Barium in Various Water Samples Using Differential Pulse Anodic Stripping Voltammetry

This work presents a reliable, cost-effective, rapid and in-field voltammetric method for the detection of barium. The optimized method consists of an ultrathin mercury film deposited in situ on a glassy carbon electrode in dilute potassium chloride without deoxygenation, using differential pulse anodic stripping voltammetry (DP-ASV). Application of the method allowed for the quantitative determination of barium concentration in a variety of waters and brake pad dust samples. Comparative analysis of sample results from DP-ASV with inductively coupled plasma mass spectroscopy (ICP-MS) showed a mean percent difference of 1.8%.

Synthesis, characterisation and in situ colorimetry of electrochromic Ruthenium purple thin films

Ruthenium purple (RP) films on transmissive tin-doped indium oxide (ITO)/glass substrates have been synthesised by an electrochemical coagulation technique using an aqueous RP colloidal suspension prepared from separate very dilute aqueous solutions of iron(III) chloride and potassium hexacyanoruthenate(II), with dilute potassium chloride as supporting electrolyte solution. To aid stability of the RP films, ruthenium(III) chloride was added to the RP colloidal suspension. Using the CIE (Commission Internationale de l’Eclairage) system of colorimetry, the colour stimulus of the electrochromic RP films and the changes that take place on reversibly switching to the colourless form have been calculated from in situ visible spectra recorded under electrochemical control. On electrochemical reduction, the intensely absorbing bright purple mixed-valence iron(III) hexacyanoruthenate(II) chromophore is reduced to the colourless iron(II) hexacyanoruthenate(II) form. Sharp and reversible changes in the hue and saturation occur, as shown by the track of the CIE 1931 xy chromaticity coordinates. Concurrently, as the purple chromophore is bleached, a large increase in the relative luminance of the electrochromic film is observed. For the purple state, the CIELAB 1976 colour space coordinates were L* = 64, a* = 27 and b* = −36, with a complementary wavelength ( λ c) calculated as 555 nm, in excellent agreement with the absorption maximum ( λ max) of 550 nm for the intervalence charge-transfer (IVCT) band.

Formation of fine crystals of potassium chloride dissolved in aqueous ethanol solution by spray evaporation

Spray evaporation of aqueous ethanol solution with dilute potassium chloride (KCl) was examined for the generation of extremely small electrolyte crystals in dry state. Ethanol content in the aqueous solution played an important role in decreasing the solubility of KCl. Evaporation of small liquid droplets of the aqueous ethanol solution produced a small amount of KCl crystals. The concentration of ethanol in the solution was the operative variable, and the ultrasonic spray nozzle and flow rate of the solution were fixed in this study. The crystals collected were observed by SEM, and crystal size distributions were obtained for different operative conditions. The average crystal size ranged from 100 to 800 nm. When the ethanol content increased in the solution, the crystal size decreased. We consider the crystal size according to the slight solubility of KCl in liquid droplets of aqueous ethanol solution.

Effect of Degassing on the Electrical Conductivity of Pure Water and Potassium Chloride Solutions

Recently, a significantly higher value was reported for the conductivity of pure water, in the absence of dissolved gases. These initial observations have been repeated in this study but with an improved experimental system, giving more accurate results than those reported in the initial experiments. Also reported here are measurements of the conductivity of pure water as a function of temperature and the extent of dissolved gas removal. In addition to the pure water studies, the effect of dissolved gas on the conductivity of dilute potassium chloride salt solutions was also examined.

Atrazine degradation and transport in runoff on a Black Vertosol

In Australia communities are concerned about atrazine being detected in drinking water supplies. It is important to understand mechanisms by which atrazine is transported from paddocks to waterways if we are to reduce movement of agricultural chemicals from the site of application. Two paddocks cropped with grain sorghum on a Black Vertosol were monitored for atrazine, potassium chloride (KCl) extractable atrazine, desethylatrazine (DEA), and desisopropylatrazine (DIA) at 4 soil depths (0–0.05, 0.05–0.10, 0.10–0.20, and 0.20–0.30 m) and in runoff water and runoff sediment. Atrazine + DEA + DIA (total atrazine) had a half-life in soil of 16–20 days, more rapid dissipation than in many earlier reports. Atrazine extracted in dilute potassium chloride, considered available for weed control, was initially 34% of the total and had a half-life of 15–20 days until day 30, after which it dissipated rapidly with a half life of 6 days. We conclude that, in this region, atrazine may not pose a risk for groundwater contamination, as only 0.5% of applied atrazine moved deeper than 0.20 m into the soil, where it dissipated rapidly. In runoff (including suspended sediment) atrazine concentrations were greatest during the first runoff event (57 days after application) (85 µg/L) and declined with time. After 160 days, the total atrazine lost in runoff was 0.4% of the initial application. The total atrazine concentration in runoff was strongly related to the total concentration in soil, as expected. Even after 98% of the KCl-extractable atrazine had dissipated (and no longer provided weed control), runoff concentrations still exceeded the human health guideline value of 40 µg/L. For total atrazine in soil (0–0.05 m), the range for coefficient of soil sorption (Kd) was 1.9–28.4 mL/g and for soil organic carbon sorption (KOC) was 100–2184 mL/g, increasing with time of contact with the soil and rapid dissipation of the more soluble, available phase. Partition coefficients in runoff for total atrazine were initially 3, increasing to 32 and 51 with time, values for DEA being half these. To minimise atrazine losses, cultural practices that maximise rain infiltration, and thereby minimise runoff, and minimise concentrations in the soil surface should be adopted.

Activity and Osmotic Coefficients of Dilute Potassium Chloride Solutions at 273 K.

Activity and Osmotic Coefficients of Dilute Potassium Chloride Solutions at 273 K.

Freezing Point Depressions of Dilute Potassium Chloride Solutions.

Freezing Point Depressions of Dilute Potassium Chloride Solutions.

Osmotic and activity coefficients in dilute potassium chloride solutions at 25 °C

Osmotic and activity coefficients of dilute aqueous potassium chloride solutions are calculated from the simplified forms of the Stokes and Robinson equation. The hydration parameters in these equations are obtained from the vapor pressure data measured at higher concentration regions and the ion-size parameter is chosen as the sum of the crystallographic radii of the cation and anion of the electrolyte. The results are very satisfactory in comparison with existing data.

The extraction of beef bones with water, dilute sodium hydroxide and dilute potassium chloride.

AbstractTo investigate the recovery of waste meat on bones, crushed beef bones were extracted under various conditions within a temperature range of 50 to 125 ºC and a pH range of 6.3 to 11.6. The extracts were analysed for total solids, collagen, non‐collagen protein, non‐protein nitrogen, creatinine and ash. The water extraction of collagen increased and of non‐collagen protein decreased with increases in temperature up to 100 ºC and the total yield of protein markedly increased with alkaline pH.

Interactions of silicate and phosphate in a lateritic soil

The use of silicates to improve the efficiency of phosphate utilization from a lateritic soil in pots produced only transient effects which, at the best, did not last longer than 1 year. Laboratory investigations with this soil in dilute potassium chloride and calcium chloride systems showed that the proportion of phosphate left in solution increased with the pH and varied as follows for the different treatments: phosphate and silicate added together >phosphate after silicate pretreatment >phosphate alone >silicate after phosphate pretreatment >water after phosphate pretreatment. The levels of phosphate in solution were smaller for the calcium chloride than for the potassium chloride systems but the levels of silicate in solution were similar for the two systems and varied with the pH as found previously. The silicate did not appear to change the type of reaction by which phosphate is fixed but rather altered the equilibrium constants involved.

The Ionic Conductivity of Dilute Potassium Chloride Solutions at Centimetric Wavelengths

A differential method is described for measuring the ionic conductivity of potassium chloride solutions at 3 × 109 c/s. The results reveal that a strong dispersion region exists at concentrations below 0.5 normal, which may be explained in terms of the perturbations by the applied field of a shell of water molecules surrounding the ion at a mean distance of 6 A.

Use of a Magnetic Field in Detecting Corrosion Currents

WHEN a drop of dilute potassium chloride solution is placed on a horizontal sheet of freshly abraded iron, corrosion occurs at the centre of the drop, but the periphery remains unattacked1. This phenomenon is commonly ascribed to electric currents flowing between the (well-aerated) peripheral zone as cathode and the (less well-aerated) central zone as anode. In several analogous cases, such as partly immersed plates of metal, the electric currents have been measured and found to be sufficiently strong to account for the whole of the corrosion observed2. The study of the currents flowing in drops has been somewhat less direct, and the following experiment may possess general interest.

The theory of metallic corrosion in the light of quantitative measurements.—Part III

The present paper describes an investigation into the degree of reproducibility obtainable by the oxygen absorption method of measuring corrosion, and gives comparative results for this and the loss of weight method. The work described in Part II which dealt with the corrosion of zinc in dilute potassium chloride has been extended up to 4N solution, and to a series of potassium sulphate solutions from N/10,000 to N. Slight vibration of the apparatus has been found to have been the source of error in three of the experiments described in Part II, namely those performed in N/200 and N/10 KCl. The corrosion-time curves for these solutions show too steep a slope owing to convection of oxygen set up by the vibration. Curves more nearly representing corrosion in truly stagnant conditions are given in fig. 4 of the present paper. The effect of vibration was only important in those experiments which were controlled by the rate of oxygen supply, whereas most of the experiments of Part II were controlled by the concentration of chlorine ions.