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13DOI: 10.6060/ivkkt.20206302.6070 УДК: 544.6.018.44
КОНСТАНТЫ ЭЛЕКТРОЛИТИЧЕСКОЙ ДИССОЦИАЦИИ СУЛЬФАТОВ ЛИТИЯ, НАТРИЯ
И КАЛИЯ В ВОДНО-ЭТАНОЛЬНЫХ РАСТВОРАХ
И.М. Борисов, А.А. Набиев
Иван Михайлович Борисов, Аъзамджон Абдухалимович Набиев*
Кафедра химии, Башкирский государственный педагогический университет им. М. Акмуллы, ул. Октябрьской революции, 3а, Уфа, Российская Федерация, 450008 Е-mail: borisovIM@yandex.ru, azamjon.94@inbox.ru*
Кондуктометрическим методом определены константы электролитической диссоциации сульфатов лития, натрия и калия в водно-этанольныхрастворах при 25 °С. LiSO^ Na2SÜ4, K2SO4 показали снижение их способности к диссоциации. Общепризнано, что степень электролитической диссоциации электролитов в растворе зависит от диэлектрической проницаемости растворителя. Вода и этанол сильно различаются диэлектрической проницаемостью. Поэтому можно получать растворители с различной диэлектрической проницаемостью путем изменения содержания спирта в смеси с водой, таким образом влияя на равновесное состояние соли в растворе. Поэтому в водно-этанольных растворах с увеличением содержания спирта сульфаты лития, натрия и калия должны проявлять свойства слабого электролита. В этом случае зависимость молярной электропроводности от концентрации сульфатов лития, натрия и калия в водно-этанольных растворах будет иметь другой вид. Действительно, с увеличением содержания спирта в водно-этанольных растворах снижается молярная электропроводность вследствие понижения степени электролитической диссоциации. С понижением концентрации соли в растворе возрастает молярная электропроводность, приближаясь к ко, как для водного, так и для водно-спиртовых растворов. Как следует из полученных данных, зависимость к от Co(M2SO4), (M2SO4 - начальные концентрации Li2SO4, Na2SO4, K2SO4) для водного раствора с высоким коэффициентом корреляции трансформируется в прямую линию в координатах уравнения Кольрауша, так как сульфаты лития, натрия и калия в водной среде выступают сильными электролитами. Для водно-эта-нольных растворов высокий коэффициент корреляции в координатах уравнения 4k3Co(M£O4)2= Кдис ко3 - Кдиско2^к наблюдается в случае [C2HsOHJ>50 % объемных. Это означает, что в этих растворах сульфаты лития, натрия и калия проявляют свойства слабого электролита. При содержании спирта от 10% до 40% об. сульфаты лития, натрия и калия выступают электролитом средней силы, и поэтому характерны низкие коэффициенты корреляции для трансформаций в координатах уравнений Кольрауша и 4k3•Co(M2SO4)2= Кдис ко3 - Кдиско2к
Ключевые слова: водно-этанольные растворы сульфатов лития, натрия и калия, кондуктометрия, константы электролитической диссоциации
CONSTANT OF ELECTROLYTIC DISSOCIATION OF LITHIUM, SODIUM AND POTASSIUM SULPHATES IN AQUEOUS ETHANOL SOLUTIONS
I.M. Borisov, A.A. Nabiev
Ivan M. Borisov, Azamdzhon A. Nabiev*
Department of Chemistry, M. Akmulla Bashkir State Pedagogical University, October Revolution st., 3a, Ufa, 450008, Russia
E-mail: BorisovIM@yandex.ru, Azamjon.94@inbox.ru*
Constants of electrolytic dissociation of the lithium, sodium and potassium sulphates in aqueous ethanol solutions at 25 °C were determined by conductometric method. Li2SO4, Na2SO4, K2SO4 were shown to decrease their ability to dissociation. It is generally accepted that the degree of electrolytic dissociation of electrolytes in a solution depends on the dielectric constant of the solvent. Water and ethanol differ greatly in their dielectric constant. For this reason, it is possible to prepare the solvent with different dielectric permittivity by changing the alcohol content in a mixture with water, thus, influencing the equilibrium state of the salt in solution. Therefore, in water-ethanol solutions with an increase in the alcohol content, sulfates of lithium, sodium and potassium should exhibit the properties of a weak electrolyte. In this case, the dependence of the molar conductivity on the concentration of sulfates of lithium, sodium and potassium in water-ethanol solutions will have a different appearance. Indeed, with an increase in the alcohol content in aqueous ethanol solutions, the molar conductivity decreases due to a decrease in the degree of electrolytic dissociation. With a decrease in the salt concentration in the solution, the molar electrical conductivity increases, approaching X0, for both water and water-alcohol solutions. As it follows from the obtained data, the dependence of X on the total concentrations of Li2SO4, Na2SO4, K2SO4) for the water solution with a high correlation coefficient is transformed into a straight line in the coordinates of the Kolraush equation since the sulfates of lithium, sodium and potassium act as strong electrolytes in the aqueous medium. For water-ethanol solutions, a high correlation coefficient in the coordinates of the equation 4X3^ C0M2SO4)2 = Kdis • X03 - Kdis - X02X is observed in the case of [CH5OH]> 50% of the volume. This means that in these solutions lithium, sodium and potassium sulphates exhibit the properties of a weak electrolyte. When the alcohol content is from 10% to 40% by volume, sulfates of lithium, sodium and potassium are medium-strength electrolyte and, therefore, low correlation coefficients are characteristic of transformations in the coordinates of the equations Kohlrausch and 4X3^ C0M2SO4)2 = Kdis • X03 - Kdis - X02X.
Key words: aqueous ethanol, lithium sulphate, sodium sulphate, potassium sulphate, conductometry, electrolytic dissociation constants
Для цитирования:
Борисов И.М., Набиев А.А. Константы электролитической диссоциации сульфатов лития, натрия и калия в водно -этанольных растворах. Изв. вузов. Химия и хим. технология. 2020. Т. 63. Вып. 2. С. 26-31
For citation:
Borisov I.M., Nabiev A.A. Constant of electrolytic dissociation of lithium, sodium and potassium sulphates in aqueous ethanol solutions. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. [Russ. J. Chem. & Chem. Tech.]. 2020. V. 63. N 2. P. 26-31
INTRODUCTION aqueous-ethanol solutions the degree of electrolytic
Information about the electrochemical proper- dissociation of sodium sulphate decreases with m-
ties of aqueous organic solutions of alkali metal sul- creasing ff^ concentrfion. In this case, Na2S°4 is
phates is extremely scarce. However, this information converted fr°m a strong ebrtrdyte m an aqueous s°-can serve as a theoretical and scientific basis for creat- lution to ann of medium or low f™^ inn
ing more optimal conditions for the processing and pu- aqueous ^^ jsolutions, depending ™ the fœM rification of inorganic salts. The authors [1, 2] showed c™tent. ^ ^ Was and th?. regularities
a decrease in the electrical conductivity of sodium sul- of electrolytic dissociation of lithium, sodium and po-phate in aqueous acetone and aqueous dioxane and pro- sulphates in aqueous ethand solutions were
posed mathematical equations describing the depend- studied.
ence of the conductivity on the salt concentration. The EXPERIMENTAL PART
physicochemical properties of lithium, sodium, and
potassium sulphates in aqueous solutions and melts
were described in [3-6]. However, in the literature,
there are practically no data on the physicochemical
.. n ,, ,• . , 11.,. • 1 pure) sodium sulphate of brand С.Р. and potassium
properties of alkali metal sulphates in aqueous-alco-
, , , .. nm ii-i* л j. j.1 1 sulphate of brand С.Р. were additionally purified by
holic solutions. The authors of 17-111 indicate the rele- ^ ,,• ^ » ^ • ^ г- \Л , , , ,
j . • 1 r- r-^j- J.U и ■ recrystallization. A certain amount of ethyl alcohol
vance and practical significance of studying the physi-
was added to the initially prepared saturated aqueous
cochemical properties of inorganic salts in aqueous-or-
solutions of lithium, sodium and potassium sulphates. ganic solutions. Earlier, in [12], we have shown that in > r r
The dietary ethanol used in the experiment was rectified, the residual water concentration was 4% by volume. Sulphate lithium of brand "С.Р. (chemically
The resulting water-ethanol salt solutions were brought to a state of equilibrium by mixing with magnetic stirrers. The achievement of equilibrium state in the studied systems was checked by microcrystalline method [13]. The concentration of salts in saturated solutions was determined according to (R.S.S.) GOST [14], by titration with barium chloride in the presence of an indicator, dichromate. Specific electrical conductivity of sodium sulphate solutions x (Ohm-1-m-1) was determined using a conductometer "HM-200". The molar conductivity A (Ohm-1 mol-1 m2) was found by the formula A = x 1000/C0(M2SO4)2, where C>(M2SO4) is the initial concentration of U2SO4, N2SO4, K2SO4.
During the main experiment, the original saturated solution was tenfold diluted using solvent (water was used as a solvent for aqueous solutions, and water-ethanol solutions were diluted by corresponding mixture of water with ethanol). The intrinsic electrical conductivity of the used solvents was determined experimentally. It was no more than 1% of the electrical conductivity of the solution.
RESULTS AND DISCUSSION
It is known [15, 16] that the solubility of lithium, sodium and potassium sulphates decreases with increasing alcohol content in a solution. The concentrations of salts in saturated water-ethanol solutions were determined by the method of volumetric titration described in [14] (Table 1).
Table 1
Molar concentrations of alkali metal sulphates in saturated aqueous ethanol solutions. Т=25 °C Таблица 1. Молярные концентрации сульфатов щелочных металлов в насыщенных водно-этанольных
паотоппа-г Т=")Ч °Г
[H20]:[C2H50H], Volume fractions, % C0(Li2S04) Mol/L C0(Na2S04) Mol/L C0(K2S04) Mol/L
100:0 3.313 1.965 0.692
90:10 2.211 0.961 0.441
80:20 1.553 0.383 0.161
70:30 1.061 0.161 0.105
60:40 0.742 0.076 0.058
50:50 0.432 0.052 0.022
40:60 0.183 0.038 0.015
30:70 0.089 0.016 0.009
20:80 0.031 0.008 0.005
10:90 0.007 0.005 0.002
During the injection of alcohol not just the concentration but also the mass fraction of salt in the studied solutions decreases. In Table 2 the evidence of decreasing solubility of sulphate alkali metals in three-component systems: Li2SO4-H2O-C2ftOH, N2SO4-H2O-C2H5OH and K2SO4-H2O-C2H5OH at 25 °C both described in the literature [15, 16] and obtained by us additionally in the field of low salt concentrations in the system is given.
Table 2
The solubility of sulfates of lithium, sodium and potassium in water-ethanol solutions. Т= 25 °C
The composition of a saturated solution, wt.%
System Li2S04-H20-C2Hs0H System Na2S04-H20-C2Hs0H System K2S04-H20-C2H50H
Li2S04 H20 C2H50H Na2S04 H20 C2H50H K2S04 H20 C2H50H
25.60 74.40 0.00 21.90 78.10 0.00 11.10 88.90 0.00
19.80 73.65 6.55 12.22 80.62 7.16 7.25 84.40 7.50
15.08 70.77 14.15 5.32 78.90 15.78 2.84 80.97 16.19
11.04 66.25 22.71 2.36 72.71 24.93 1.80 73.10 25.10
8.13 59.91 31.96 1.16 64.46 34.38 1.10 64.50 34.40
4.99 52.79 42.22 0.81 55.10 44.08 0.42 55.28 44.30
2.24 44.43 53.33 0.61 45.18 54.21 0.31 45.29 54.40
1.13 34.49 64.38 0.26 34.80 64.94 0.18 34.82 65.00
0.41 23.71 75.88 0.14 23.78 76.09 0.11 23.78 76.10
0.09 12.18 87.72 0.09 12.18 87.73 0.04 12.16 87.76
It can be seen from the Table 2 that with the increase in alcohol concentration the solubility of lithium, sodium and potassium sulphates decreases more than two-fold. In our opinion, it is caused by the change in the dielectric constant of the liquid phase. Water (s = 78.53) and ethanol (s = 24.30) differ sufficiently in dielectric permittivity. In that way, it is possible to
prepare the solvent with different dielectric permittivity by changing the alcohol content in a mixture with water, thus, affecting the equilibrium state of the salt in solution. When calculating the Table 2 data, the experimentally determined values of the density of saturated solutions of lithium, sodium and potassium sulphates in aqueous ethanol solutions were used (Table 3).
The decrease in the density of solutions is caused not only by the addition of alcohol, which has a lower density compared to water, but also by a decrease in the concentration of dissolved salt.
The characteristic of electrolytic dissociation of lithium, sodium and potassium sulphates were studied by conductometric method, same as in [12], by finding the dependence of molar conductivity on the salt concentration in the solution. The concentration of Li2SO4, Na2SO4, K2SO4 was varied by diluting the saturated solutions with an appropriate solvent (water or aqueous ethanol). In aqueous solutions, the sulphates of lithium, sodium and potassium are strong electro-
lytes and, therefore, the interdependence of molar conductivity and salt concentration obeys the equation Kohlrausch [17-21].
I = - a-Co(M2SO4)v
(1)
where 1 is the molar electrical conductivity of the solution; I0 is the maximum molar electrical conductivity of the solution; Co(M2SO4) is the initial concentration of lithium, sodium or potassium sulphate; a is the parameter characterizing the electrophoretic and relaxation effects of ion inhibition.
At low concentrations of ethanol (10-40% vol.) in a solution Li2SO4, Na2SO4, K2SO4 exhibit the properties of an electrolyte of medium strength [12].
Table 3.
The density of saturated solutions of lithium, sodium and potassium sulfates in water-ethanol solutions. Т= 25 °C Таблица 3. Плотность насыщенных растворов сульфатов лития, натрия и калия в водно-этанольных рас-
[H20MC2H5OH], Volume fractions in% p (Н2О + C2H5OH) kg/m3 p (Н2О + C2H5OH + M2SO4) kg/m3
LÎ2SO4 Na2SO4 K2SO4
100:0 997.05* 1245.01 1240.02 1093.01
90:10 984.71 1150.04 1175.04 1035.05
80:20 973.62 1095.02 1100.03 990.06
70:30 962.21 1040.01 1000.01 966.01
60:40 948.01 1000.04 950.04 950.04
50:50 930.23 970.03 940.03 911.03
40:60 909.11 950.01 920.01 901.07
30:70 885.52 902.04 885.02 878.09
20:80 859.34 890.02 865.04 858.04
10:90 829.21 860.01 845.03 839.01
— "»S о
* The data from [17] was used, the density of the solvent (mixture of water with ethanol) was found experimentally
* Использованы данные из [17], плотность растворителя найдена экспериментально (смесь воды с этанолом)
At a certain concentration of alcohol in the solution (> 50% vol.), these salts become the weak electrolytes and, therefore, they are characterized by the following equation [12]:
413-C0(M2SO4)2 = KdisV - Kdis 102-1 (2) From the linear graphic dependence 413-C0(M2SO4)2 on 1 (Figure) the slope tangent, which is equal to Kdis I02, and the intercept (which is equal to Kdis103), were determined.
These values were used to determine
I0 = Kdis^0 /Kdis^0 (3)
and salt dissociation constants in aqueous ethanol solution
Kdis = slope angle tangent/102 (4)
The obtained values of the electrolytic dissociation constants of the studied salts are summarized in the Table 4.
Therefore, as we can see from the Table 4, the values of the dissociation constant of alkali metal sulphates with increasing alcohol concentration decreases. This is due to the decrease in the polarity of the liquid phase during the transition from a strongly
0,0020 0,0026 D.003D 0 0035 0,0040 0.004S
Fig. The linear dependence of molar conductivity on the concentration of lithium sulfate in the coordinates of equation (2). [Н2О]: [C2H5OH]= 10:90, volume percentages. The correlation coefficient is 0.9999
Рис. Линейная корреляция зависимости молярной электропроводности от концентрации сульфата лития в координатах уравнения (2). [Н2О]: [C2H5OH] = 10:90 объемные доли в %. Коэффициент корреляции равен 0,9999
polar solvent (water) to a mixture with less polar (ethanol). The data of Table 4 also clearly indicate the influence of the nature of the salt on the value of the electrolytic dissociation constant: with an increase in the
Table 4
Values of electrolytic dissociation constants of lithium, sodium and potassium sulphates in aqueous ethanol solutions Т = 25 °С
Таблица 4. Значения констант электролитической диссоциации сульфатов лития, натрия и калия в водно -
этанольных растворах. Т = 25 °С
Volume fraction of ethanol, % vol. Kdis (mol/l)2
Li2S04 Na2S04 K2S04
50 (3.54±0.01)10-3 (1.95±0.01)10-3 (2.42±0.01)10-6
60 (1.01±0.31)10-3 (5.97±0.01)10-4 (1.25±0.06)10-6
70 (6.54±0.21)10-4 (2.29±0.05)10-4 (8.96±0.02)10-7
80 (1.08±0.01)10-4 (2.31±0.01)10-5 (6.20±0.40)10-7
90 (3.80±0.03)10-5 (1.77±0.02)-10-5 (1.06±0.01)10-7
size of the cation, the electrolytic dissociation constant decreases. The total effect of these factors seems to reduce the polarity of the oxygen-metal bond, which reduces Kdis.
Using the more sensitive conductometer and finding the salt concentration in the solution by volume titration instead of the gravimetric one allowed us to clarify the values of the electrolytic dissociation constants Na2SO4, which were previously given in [12].
The data obtained as a reference data can be used as a theoretical and scientific basis for cleaning and obtaining inorganic substances [12]. For the first time, concentrations of lithium, sodium, and potassium sulphates in water-ethanol solutions with different al-
ЛИТЕРАТУРА
1. Крижановский А.В., Ненно Э.С., Скрипченко Р.М.
Система Na2SO4-(CH3)2CO - H2O. Журн. неорган. химии. 1972. Т. 17. № 9. С. 2526-2530.
2. . Крижановский А.В., Ненно Э.С. Система Na2SO4-C4H8O2 - H2O. Журн. неорган. химии. 1973. Т. 18. № 8. С. 2262-2265
3. Журавлев Ю.Н., Журавлева Л.В., Головко О.В. Химическая связь в сульфатах щелочных металлов. Журн. структур. химии. 2007. Т. 48. №5. С. 849-856.
4. Солиев Л., Джумаев М.Т., Низомов И.М., Тошов А.Ф. Растворимость системы Na2SO4-Na2CO3-NaHCO3-H2O при 25 °С. Докл. АНРТ. 2015. Т. 58. № 9. С. 827-834.
5. Солиев Л., Худоёрбекова З.П., Низомов И.М. Фазовые равновесия в системе K2SO4-K2CO3-KHCO3-H2O при 25 °С. Докл. АН РТ. 2016. Т. 59 № 5-6. С 236-240.
6. Денисов Г.С., Матымбеков У.К Инфракрасные спектры кристаллов K2SO4 и Na2SO4. Вестн. КРСУ. 2009. Т. 9. № 11. С. 153-157.
7. Смотров М.П., Уметчиков В.А., Данилина В.В., Черкасов Д.Г. Фазовые равновесия и растворимость компонентов в двойной системе вода-дипропиламин. Изв. Са-рат. ун-та. Нов. сер. Сер. Химия. Биология. Экология. 2018. Т. 18. Вып. 4. С. 378-382. DOI: 10.18500/1816-97752018-18-4-378-382.
8. Ильин К.К. Обобщение схема топологической трансформаций фазовых диаграмм тройных расслаивающихся систем соль-бинарный растворитель с высаливанием. Изв. Сарат. ун-та. Нов. сер. Сер. Химия. Биология. Экология. 2009. Т. 9. № 1. С. 3-7.
cohol contents were determined using the bulk titration method.
In Table 4 data, two regularities of electrolytic dissociation of salts are observed. First, a decrease in the dissociation constants of alkali metal sulphates with an increase in the volume fraction of ethanol indicates that alcohol additives significantly reduce the degree of electrolytic dissociation of salts. Second, the constant, hence the degree, of electrolytic dissociation depends on the nature of the cation and decreases in the row Li-Na-K.
Работа выполнена при финансировании за счет средств научного гранта Башгоспедунивери-стета им. М. Акмуллы № 66/н от 14.06.2019.
REFERENCES
1. Krizhanovsky A.V., Nenno E.S., Skripchenko R.M. The
system Na2SO4- (СНз)2СО - H2O. Zhurn. Neorgan. Khim. 1972. V. 17. N 9. P. 2526-2530 (in Russian).
2. Krizhanovsky A.V., Nenno E.S. The system Na2SO4-C4HgO2 -H2O. Zhurn. Neorgan. Khim. 1973. V. 18. N 8. Р. 2262-2265 (in Russian).
3. Zhuravlev Yu.N., Zhuravleva L.V., Golovko O.V. Chemical bond in alkali metal sulphates. Zhurn. Strukt. Khim. 2007. V. 48. N 5. Р. 849-856 (in Russian).
4. Soliev L., Jumaev M.T., Nizomov J.M., Toshov A.F. Solubility of the system Na2SO4-Na2CO3-NaHCO3-H2O at 25 °C. Dokl. ANResp.Tajik. 2015. V. 58 N 9. Р. 827-834 (in Russian).
5. Soliev L., Khudoyerbekova Z.P., Nizomov I.M. Phase equilibria in the K2SO4-K2CO3-KHCO3-H2O system at 25 °C. Dokl. AN Resp.Tajik.. 2016. V. 59. N 5-6. Р. 236-240 (in Russian).
6. Denisov G.S., Matimbekov U.K. Infrared spectra of K2SO4 and Na2SO4 crystals. Vest. KRSU. 2009. V. 9. N 11. P. 153-157 (in Russian).
7. Smotrov M.P., Umetchikov V.A., Danilina V.V., Cherkasov
D.G. Phase equilibria and solubility of components in the water - dipropylamine binary system. Izv. Sarat. Un-ta. Nov. Ser. Khim. Biol. Ekolog. 2018. V. 18. N 4. Р. 378-382 (in Russian). DOI: 10.18500/1816-9775-2018-18-4-378-382.
8. Ilyin K.K. Generalization of the topological transformation scheme of the phase diagrams of triple exfoliating systems is a salt-binary solvent with salting out. Izv. Saratov University.Ser. Khim. Biol. Ekolog. 2009. V. 9. N 1. P. 3-7 (in Russian).
9. Ильин К.К., Синегубова С.И. Слово об учителе: К 90- 9. летию со дня рождения профессора Н.И. Никурашиной. Химические науки-2006: Сб. науч. тр. Вып. 3. Саратов: Изд-во «Научная книга». 2006. С. 3-13.
10. Черкасов Д.Г., Чепурина З.В., Ильин К.К. Топологи- 10. ческая трансформация фазовой диаграммы разреза 2 тетраэдра состава четверной системы нитрат калия - вода -пиридин - масляная кислота в интервале 5-60 °С. Изв. Сарат. ун-та. Нов. сер. Сер. Химия. Биология. Экология. 2018. Т. 18. Вып. 3. С. 278-284. DOI: 10.18500/1816-97752018-18-3-278-284.
11. Мешкова А.А., Сафонова В.Д., Гартман Т.Н. Разра- 11. ботка процедур расчета химико-технологических схем с учетом реакции диссоциации электролитов в неорганических системах Усп. в химии и хим. технологии. 2014. Т. 28.
№ 2 (151). С. 24-27.
12. Борисов И.М., Набиев А.А., Мухамедьянова А.А., Со- 12. лиев Л., Тошов А.Ф., Мусоджонова Дж.М. Электролитическая диссоциация сульфата натрия в водно-этаноль-ных растворах. Изв. вузов. Химия и хим. технология. 2017. Т.60. Вып. 6. С. 59-64.
13. Кочетков О.С. Основы кристаллооптики и микроскопи- 13. ческий анализ. Ухта: УГТУ. 2006. 35 с.
14. Межгосударственный совет по стандартизации, метро- 14. логии и сертификации. ВОДА ПИТЬЕВАЯ методы определения содержания сульфатов. Межгосударственный стандарт ГОСТ 31940-2012.
15. Справочник по растворимости. Т.1. Бинарные системы. 15. Кн.1. М., Л. 1961. 960 с.
16. Seidell A. Linke W.F. Solubilities of inorganic and organic 16. compounds. New-York: Van Nostrand. 1952. 1254 р.
17. Franks F. Water: 2nd edition A matrix of life. Cambridge: 17. Royal society of chemistry. 2000. 236 p.
18. Дамаскин Б.Б., Петрий О.А. Цирлина Г.А. Электрохи- 18. мия. М.: Химия, Колос С. 2006. 672 с.
19. Сваровская Н.А., Колесников И.М., Винокуров В.А. 19. Электрохимия растворов электролитов. Ч. I. Электропроводность. М.: Изд. центр РГУ нефти и газа (НИУ) им. И.М. Губкина. 2017. 66 с.
20. Артемкина, Ю.М., Понамарева Т.Н., Кириллов А.Д., Щербаков В.В. Физико-химические свойства растворов 20. и неорганических веществ. Сб. научн. тр. Вып. 182. М.: РХТУ им. Д.И. Менделеева. 2008. С. 83-90, 91-98.
21. Аллахвердов Г.Р. Уравнение электропроводности растворов сильных электролитов. Докл. Акад. наук. 2014. Т. 456.
№ 3. С. 287. 21.
22. Брусенцева Л.Ю., Кудряшова А.А. Краткий справочник физико-химических величин некоторых неорганических и органических соединений. Самара: НОУ ВПО 22 СМИ «РЕАВИЗ». 2011. 68 с.
Ilyin K.K., Sinegubova S.I. A word about the teacher: To the 90th birthday of professor N.I. Nikurashina. Chemical Sciences-2006: Sat. scientific tr. Iss. 3. Saratov: Publishing House "Scientific Book". 2006. P. 3-13 (in Russian). Cherkasov D.G., Chepurina Z.V., Ilyin K.K. Topological transformation of the phase diagram of a section 2 tetrahedrons of the composition of the quadruple system of potassium nitrate - water - pyridine - butyric acid in the range of 5-60 °C. Izv. Sarat. Un-ta. Nov. Ser. Khim.. Biol. Ekolog. 2018. V. 18. N 3. P. 278-284 (in Russian). DOI: 10.18500 / 1816-9775-2018-18-3-278-284.
Meshkova A.A., Safonova V.D., Gartman T.N. Development of procedures for the calculation of chemical-technological schemes, taking into account the dissociation of electrolytes in inorganic systems. Usp. Khim. Khim. Tekhnol. 2014. V. 28. N 2 (151). P. 24-27 (in Russian). Borisov I.M., Nabiev A.A., Mukhamedyanova A.A., Soliev L., Toshov A.F., Musodzhonova Dzh.M. Electrolytic dissociationof sodium sulfate in aqueous ethanol solutions. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 6. P. 59-64 (in Russian). DOI: 10.6060/tcct.2017606.5535. Kochetkov O.S. Basics of crystal optics and microscopic analysis. Methodical instructions. Ukhta. UGTU. 2006., 35 p. Interstate Council for Standardization, Metrology and Certification. Water drinking methods for the determination of sulfate conten: Interstate standard GOST 31940-2012 (in Russian).
Handbook of solubility. V.1. Binary Systems.Book 1. M., L. 1961. 960 p. (in Russian).
Seidell A. Linke W.F. Solubilities of inorganic and organic compounds. New-York: Van Nostrand. 1952. 1254 p. Franks F. Water: 2nd edition A matrix of life. Cambridge: Royal society of chemistry. 2000. 236 p. Damaskin B.B., Petriy O.A., Tsirlina G.A. Electrochemistry. M.: Khimiya. Kolos S. 2006. 672 p. (in Russian). Svarovskaya N.A., Kolesnikov I.M., Vinokurov V.A. Electrochemistry of electrolyte solutions. Part I. Electrical Conductivity: A Tutorial. M.: Publishing Center of the Russian State University of Oil and Gas named after I.M. Gub-kina. 2017. 66 p. (in Russian).
Artemkina Yu.M., Ponamareva T.N., Kirillov A.D., Shcherbakov V.V. Physico-chemical properties of solutions and inorganic substances: Coll. scientific works Iss. 182. M.: D. Mendeleev University of Chemical Technology of Russia. 2008. P. 83-90, 91-98 (in Russian).
Allakhverdov G.R. The equation of the electrical conductivity of solutions of strong electrolytes. Dokl. AN. 2014. V. 456. N 3. P. 287 (in Russian).
Brusentseva L. Yu., Kudryashova A.A. A brief guide to the physico-chemical values of some inorganic and organic compounds. Samara: Medical Institute. Reaviz 2011. 68 p. (in Russian).
Поступила в редакцию 03.06.2019 Принята к опубликованию 25.11.2019
Received 03.06.2019 Accepted 25.11.2019
