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Electrochemistry
Published in W. John Rankin, Chemical Thermodynamics, 2019
For comparing the conductivity of electrolytes in a solution, rather than of the solution itself, use is made of the concept of molar conductivity.† This is defined as ΛB=κc
Measurement of Electrolytic Conductance
Published in Grinberg Nelu, Rodriguez Sonia, Ewing’s Analytical Instrumentation Handbook, Fourth Edition, 2019
Stacy L. Gelhaus, William R. LaCourse
The molar conductivity, λm, is a property of ions (either positive or negative) that gives quantitative information about their relative contributions to the conductance of the solution.2,4 Arrhenius postulated in 1887 that an appreciable amount of electrolyte will dissociate into free ions in solution. This value is to some extent dependent on the total ionic concentration, increasing with increasing dilution. The molar conductivity of an electrolyte would be independent of concentration if κ were proportional to the concentration of the electrolyte.4 Unfortunately, the molar conductivity is found experimentally to vary with concentration. A possible reason for this is that the number of ions in the solution might not be proportional to the concentration of the electrolyte. The concentration of ions in a weak acid solution depends on the concentration of the acid; however, the relationship is not direct, as doubling the concentration of acid does not double the number of ions. Second, because ions interact strongly with one another, the conductivity of the solution is not exactly proportional to the number of ions present. This concentration dependence indicates that there are two possible classes—strong electrolytes and weak electrolytes. The classification of electrolytes into either category depends not only on the solute itself but also on the solvent.2
Electrochemical Composition Measurement
Published in John G. Webster, Halit Eren, Measurement, Instrumentation, and Sensors Handbook, 2017
Michael J. Schöning, Arshak Poghossian, Olaf Glück, Marion Thust
where c corresponds to the concentration of the solution in mol L−1. The units of Λ are S cm−1 mol−1. Equation 55.56 permits the calculation of the molar conductivity for a solution of known concentration by considering the experimental values of ĸ. The molar conductivity Λ, that is, the mobility of ions in solution, is mainly influenced by interionic effects for strong electrolytes and the degree of dissociation for weak solutions. For strong electrolytes, the molar conductivity increases as the dilution is increased. By linear graphical extrapolation for diluted solutions of strong electrolytes, a limiting value is defined as molar conductivity at infinite dilution Λ0. At infinite dilution, the interionic attraction is nil, the ions are independent of each other, and the total conductivity is
Synthesis and characterization of ionic liquids [C12mim]Cl, [C14mim]Cl and [C16mim]Cl: experimental and molecular dynamics simulations
Published in Liquid Crystals, 2022
Zhihao Li, Chuandong Ma, Meng He, Qingbiao Wang, Hao Yu, Xiaofang You, Lin Li
However, the success rate of testing the powdered conductivity is low, resulting in high test costs. Through molecular dynamics simulations, the conductivity of ILs was obtained. It can assist in detecting the electrical conductivity of the powder, improving accuracy, and predicting the properties of the powder sample, reducing the cost of testing. In this study, three ionic liquids [C12mim]Cl, [C14mim]Cl, [C16mim]Cl, were prepared and their densities at 293 K, 303 K and 313 K were measured. Their density, molar conductivity and conductivity were simulated. This article aims to provide the basic physico-chemical properties of a long-chain substituted imidazolium chloride salt. The influences of temperature and the alkyl-chain length on the 3-position nitrogen atom of imidazole ring on the physical and chemical properties, and the properties of ionic liquids were studied.
Solvent-induced synthesis and crystal structures of copper(II) complexes derived from 4-chloro-2-[(2-hydroxymethylphenylimino)methyl]phenol with antibacterial activity
Published in Journal of Coordination Chemistry, 2022
5-Chlorosalicylaldehyde, 2-aminobenzylalcohol, and copper chloride were purchased from Aldrich with AR grade. The solvents ethanol and dichloromethane were commercially obtained and used as received. The Schiff base H2L was prepared by 5-chlorosalicylaldehyde and 2-aminobenzylalcohol in ethanol according to the literature method [22, 23]. The mixture was stirred at reflux for 30 min, and with the solvent removed by distillation. Elemental analyses for C, H, and N were performed on a Perkin-Elmer 2400 II analyzer. Fourier Transform InfraRed (FT-IR) spectra were recorded as KBr pellets on a Bruker Tensor-27. UV–Vis spectra were recorded on a Lambda 35 spectrophotometer. Single-crystal X-ray diffraction was carried out with a Bruker Apex II CCD (Charge-coupled device) diffractometer. Molar conductivity was measured in methanol with a DDS-11A molar conductivity meter.
Metal(II) chloride complexes containing a tridentate N-donor Schiff base ligand: syntheses, structures and antimicrobial activity
Published in Journal of Coordination Chemistry, 2021
Sadeka J. Munshi, Jaswinder Kaur Saini, Sanjay Ingle, Sujit Baran Kumar
The mononuclear complexes [M(L)Cl2] [M = Cu(II), Co(II) and Zn(II)] and the polymeric complex [Cd(L)Cl2]n were obtained with good yield (>65%) upon one-pot synthesis of 1:1 molar ratio of metal chloride salt and tridentate Schiff base L in ethanol at room temperature (Scheme 2) and characterized by elemental analysis, UV-Vis and FT-IR spectroscopies and single-crystal X-ray diffraction studies. L is tridentate and has utilized all its three nitrogen donor atoms for coordination with metal ions in the mononuclear complexes but in the case of polymeric cadmium(II) complex, L has utilized only two nitrogen donor atoms for coordination. The coordination of L in the metal centers were confirmed by FT-IR and single-crystal X-ray diffraction studies. Mononuclear complexes are five-coordinate with distorted square pyramidal geometry but the polynuclear Cd(II) complex has six-coordination and the geometry around Cd center is distorted octahedral. Molar conductivity measurements in CH3CN show that all the complexes are non-electrolyte and there was no change in conductivity even after 3 h, indicating no dissociation of the complexes in solution. The compounds are soluble in all common organic solvents like acetonitrile, methanol, ethanol, acetone, dichloromethane, etc.