Concentration and temperature empirical relationships of the electrical conductivity of electrolyte solutions
We have considered the dependences of the specific (κ) and molar (Λ) electrical conductivity (EC) of aqueous electrolyte solutions on the molar concentration and temperature for sulfates of divalent metals (Mn, Co, Ni, Cu, Zn, Cd) in a wide concentration range at 5 – 35°C. To describe such systems w...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
V. N. Karazin Kharkiv National University
2021-05-01
|
| Series: | Вісник Харківського національного університету: Серія xімія |
| Subjects: | |
| Online Access: | https://periodicals.karazin.ua/chemistry/article/view/18681 |
| _version_ | 1827779539475890176 |
|---|---|
| author | Pavel Efimov Andrey Kramarenko Viktor Tomak |
| author_facet | Pavel Efimov Andrey Kramarenko Viktor Tomak |
| author_sort | Pavel Efimov |
| collection | DOAJ |
| description | We have considered the dependences of the specific (κ) and molar (Λ) electrical conductivity (EC) of aqueous electrolyte solutions on the molar concentration and temperature for sulfates of divalent metals (Mn, Co, Ni, Cu, Zn, Cd) in a wide concentration range at 5 – 35°C. To describe such systems we propose a modified cubic equation (MCE): κ = C∙c3k + Q∙c2k + L∙ck, where C, Q, L, k are empirical parameters, fixed parameter k = 0.5 has been considered as well. From the correlation between the calculated parameters we assume that two of them are sufficient. The maximum of specific EC (κm) and the corresponding concentration (cm) have been calculated. We also assume that the systems under study are isomorphic in the normalized coordinates (κ/κm via c/cm). For the dependences like κ = A∙cx + B∙cy it is shown that x = 1 is a good approximation over the generalized sample. Empirical dependences with y = 5/4 and y = 4/3 are also considered. It is shown that they give comparable results to MCE.
The proposed approach is tested on EC data of aqueous solutions of some salts. Similar two-parameter κ(κm, cm; c) equations of other authors have been considered. In order to describe the dependence of the specific EC on temperature and concentration we propose an equation κ = (A25 + a∙θ)∙c – (B25 + b∙θ)∙c5/4, where θ is the reduced temperature and A25, a, B25 and b are empirical parameters. Also a generalized equation for the molar EC of concentrated electrolyte solutions is proposed: Λ(Λ*, Λm, cm; c), where Λ* is the effective limiting molar EC, and Λm is the molar EC at c = cm. It was found that Λ* and Λm depend linearly on temperature. The average value of the exponent is close to 1/3, which brings the generalized molar EC equation closer to the equation derived from the quasi-lattice model of electrolyte solutions. |
| first_indexed | 2024-03-11T14:51:00Z |
| format | Article |
| id | doaj.art-a9dbac6439834a5c8b607e16c3494e77 |
| institution | Directory Open Access Journal |
| issn | 2220-637X 2220-6396 |
| language | English |
| last_indexed | 2024-03-11T14:51:00Z |
| publishDate | 2021-05-01 |
| publisher | V. N. Karazin Kharkiv National University |
| record_format | Article |
| series | Вісник Харківського національного університету: Серія xімія |
| spelling | doaj.art-a9dbac6439834a5c8b607e16c3494e772023-10-30T09:32:52ZengV. N. Karazin Kharkiv National UniversityВісник Харківського національного університету: Серія xімія2220-637X2220-63962021-05-0136445310.26565/2220-637X-2021-36-0718681Concentration and temperature empirical relationships of the electrical conductivity of electrolyte solutionsPavel Efimov0Andrey Kramarenko1Viktor Tomak2V.N. Karazin Kharkiv National University, School of Chemistry, 4 Svobody sqr., 61022 Kharkiv, UkraineNational Technical University «Kharkiv Polytechnic Institute» 2, Kyrpychova str., 61002, Kharkiv, UkraineV.N. Karazin Kharkiv National University, School of Chemistry, 4 Svobody sqr., 61022 Kharkiv, UkraineWe have considered the dependences of the specific (κ) and molar (Λ) electrical conductivity (EC) of aqueous electrolyte solutions on the molar concentration and temperature for sulfates of divalent metals (Mn, Co, Ni, Cu, Zn, Cd) in a wide concentration range at 5 – 35°C. To describe such systems we propose a modified cubic equation (MCE): κ = C∙c3k + Q∙c2k + L∙ck, where C, Q, L, k are empirical parameters, fixed parameter k = 0.5 has been considered as well. From the correlation between the calculated parameters we assume that two of them are sufficient. The maximum of specific EC (κm) and the corresponding concentration (cm) have been calculated. We also assume that the systems under study are isomorphic in the normalized coordinates (κ/κm via c/cm). For the dependences like κ = A∙cx + B∙cy it is shown that x = 1 is a good approximation over the generalized sample. Empirical dependences with y = 5/4 and y = 4/3 are also considered. It is shown that they give comparable results to MCE. The proposed approach is tested on EC data of aqueous solutions of some salts. Similar two-parameter κ(κm, cm; c) equations of other authors have been considered. In order to describe the dependence of the specific EC on temperature and concentration we propose an equation κ = (A25 + a∙θ)∙c – (B25 + b∙θ)∙c5/4, where θ is the reduced temperature and A25, a, B25 and b are empirical parameters. Also a generalized equation for the molar EC of concentrated electrolyte solutions is proposed: Λ(Λ*, Λm, cm; c), where Λ* is the effective limiting molar EC, and Λm is the molar EC at c = cm. It was found that Λ* and Λm depend linearly on temperature. The average value of the exponent is close to 1/3, which brings the generalized molar EC equation closer to the equation derived from the quasi-lattice model of electrolyte solutions.https://periodicals.karazin.ua/chemistry/article/view/18681specific electrical conductivitymolar electrical conductivityelectrolyte solutionssulfates of divalent metalsempirical equations |
| spellingShingle | Pavel Efimov Andrey Kramarenko Viktor Tomak Concentration and temperature empirical relationships of the electrical conductivity of electrolyte solutions Вісник Харківського національного університету: Серія xімія specific electrical conductivity molar electrical conductivity electrolyte solutions sulfates of divalent metals empirical equations |
| title | Concentration and temperature empirical relationships of the electrical conductivity of electrolyte solutions |
| title_full | Concentration and temperature empirical relationships of the electrical conductivity of electrolyte solutions |
| title_fullStr | Concentration and temperature empirical relationships of the electrical conductivity of electrolyte solutions |
| title_full_unstemmed | Concentration and temperature empirical relationships of the electrical conductivity of electrolyte solutions |
| title_short | Concentration and temperature empirical relationships of the electrical conductivity of electrolyte solutions |
| title_sort | concentration and temperature empirical relationships of the electrical conductivity of electrolyte solutions |
| topic | specific electrical conductivity molar electrical conductivity electrolyte solutions sulfates of divalent metals empirical equations |
| url | https://periodicals.karazin.ua/chemistry/article/view/18681 |
| work_keys_str_mv | AT pavelefimov concentrationandtemperatureempiricalrelationshipsoftheelectricalconductivityofelectrolytesolutions AT andreykramarenko concentrationandtemperatureempiricalrelationshipsoftheelectricalconductivityofelectrolytesolutions AT viktortomak concentrationandtemperatureempiricalrelationshipsoftheelectricalconductivityofelectrolytesolutions |