Electrical Conductivity, Viscosity and Molar Volume of Potassium Nitrate - Sodium Nitrate in Cadmium Nitrate Tetrahydrate Melt

1998 ◽  
Vol 51 (3) ◽  
pp. 201 ◽  
Author(s):  
Gautam Kalita ◽  
Nashiour Rohman ◽  
Sekh Mahiuddin
Keyword(s):  
Electrical Conductivity ◽  
Molar Volume ◽  
Potassium Nitrate ◽  
Present System ◽  
Cadmium Nitrate ◽  
Intrinsic Volume ◽  
Polarization Model ◽  
Mixed Alkali ◽  
Free Volume Model ◽  
Mixed Alkali Effect

The electrical conductivities, viscosities and molar volumes of the 0·3[xKNO3+(1 – x)NaNO3]+ 0·7Cd(NO3)2.4·4H2O systems were measured as functions of temperature (293·15 ≤ T/K ≤ 363·15) and composition (x = 0·0 to 1·0 mole fraction). The temperature dependence of the electrical conductivity and viscosity was non-Arrhenius in nature and has been analysed by using the Vogel–Tammann–Fulcher (VTF) equation. Both conductivity and viscosity vary non-linearly with the molar volume and have been explained by using VTF-type equations based on the free volume model. In the present system the molar volume and the intrinsic volume are additive. A significant mixed alkali effect has been observed in the normalized electrical conductivity and viscosity and in the electrical conductivity at the isofluidity condition. The variation of the electrical conductivity is governed by the mobility of the potassium ions. The onset of the mixed alkali effect has been explained by the anion polarization model.

Mixed alkali effect in 0.2[xKNO3 + (1 − x)NaNO3] + 0.8glycerol systems

1994 ◽  
Vol 72 (11) ◽  
pp. 2286-2290 ◽  
Author(s):  
Sekh Mahiuddin
Keyword(s):  
Electrical Conductivity ◽  
Temperature Dependence ◽  
Mole Fraction ◽  
Linear Functions ◽  
Present System ◽  
Polarization Model ◽  
Mixed Alkali ◽  
Temperature Dependence Of Conductivity ◽  
Mixed Alkali Effect

Density, electrical conductivity, and fluidity of 0.2[xKNO3 + (1 − x)NaNO3] + 0.8glycerol systems were measured as functions of temperature (363.15 to428.15 K) and composition (0.0to 1.0 mole fraction). Densities were linear functions of temperature. The temperature dependence of conductivity and fluidity has been analysed by using the Vogel–Tammann–Fulcher (VTF) equation. Deviation from additivity has been observed in the electrical conductivity, fluidity isotherms to a lesser extent, and in electrical conductivity under isofluidity condition. The onset of the mixed alkali effect (MAE) in the present system has been explained by the anion polarization model.

Mixed alkali effect in sodium thiocyanate–potassium thiocyanate – acetamide melt systems

1996 ◽  
Vol 74 (5) ◽  
pp. 760-765 ◽  
Author(s):  
Sekh Mahiuddin
Keyword(s):  
Electrical Conductivity ◽  
Molar Volume ◽  
Potassium Thiocyanate ◽  
Sodium Thiocyanate ◽  
Volume Data ◽  
Intrinsic Volumes ◽  
Mixed Alkali ◽  
Free Volume Model ◽  
Mixed Alkali Effect ◽  
Solvated Ions

Electrical conductivity and molar volume of the 0.25[xNaSCN + (1 −x)KSCN] + 0.75CH3CONH2 systems were measured as functions of temperature [Formula: see text] and composition (x = 0.0 – 1.0 mol fraction). Temperature dependence of the electrical conductivity was non-Arrhenius in nature and has been analysed by using the Vogel–Tammann–Fulcher (VTF) equation. Molar volume data were fitted to an equation similar to the VTF equation based on the free volume model. Molar volumes and intrinsic volumes were found to be additive in nature. Electrical conductivity isotherms deviate from linearity in different fashion for different temperature regions. The onset of the mixed alkali effect is governed by the anion polarization effect, by a contribution of the auto-dissociated molten acetamide, and by polymeric-type solvated ions. Key words: electrical conductivity, sodium thiocyanate, potassium thiocyanate, acetamide, mixed alkali effect.

scholarly journals The Electrical Conductivity of Some Hydrous and Anhydrous Molten Silicates as a Function of Temperature and Pressure

2021 ◽  
Author(s):  
◽  
John Satherley
Keyword(s):  
Electrical Conductivity ◽  
Quartz Crystal ◽  
Pressure Coefficient ◽  
General Picture ◽  
Water Composition ◽  
Mixed Alkali ◽  
Mixed Alkali Effect ◽  
Temperature And Pressure ◽  
Increasing Temperature ◽  
Arrhenius Temperature

<p>This thesis is concerned with the measurement and interpretation of electrical conductivity in molten silicates. Physicochemical properties and structural models of silica and silicates are reviewed first, to give a general picture of their behaviour. Electrical conductivity was measured as a function of temperature, pressure and water composition. To make these measurements an internally heated pressure vessel, designed to operate at temperatures up to 1200 degrees C and pressures up to 5 kbars was constructed. Conductivity measurements were made on the following anhydrous and hydrous silicate melts: SiO2/Na2O 60/40, 65/35, 75/25, 78/22 mol%; SiO2/Na2O/CaO 72/24/4 mol%; Mt. Erebus lava; SiO2/Na2O 78/22 mol% + ~5 wt% H2O and Mt. Erebus lava + ~4 wt% H2O in the temperature range 850-1000 degrees C and the pressure range 0-1.3 kbar. Arrhenius temperature and pressure dependencies on conductivity were observed. The pressure coefficient of conductivity was zero for the anhydrous melts well above Tg but small and positive for the hydrous silicates. Water caused ~40% reduction in conductivity when added to a melt which was accounted for in terms of the mixed alkali effect. Conductivity isobars for the hydrous silicates passed through a maximum as a function of increasing temperature. The conductivity behaviour as a function of temperature and pressure is analogous to that observed in partially ionised liquids and is intrepretated in an identical way. The range of operation of a piezoelectric alpha-quartz crystal viscometer was extended to allow measurement of viscosity as a function of temperature.</p>

scholarly journals The Electrical Conductivity of Some Hydrous and Anhydrous Molten Silicates as a Function of Temperature and Pressure

2021 ◽  
Author(s):  
◽  
John Satherley
Keyword(s):  
Electrical Conductivity ◽  
Quartz Crystal ◽  
Pressure Coefficient ◽  
General Picture ◽  
Water Composition ◽  
Mixed Alkali ◽  
Mixed Alkali Effect ◽  
Temperature And Pressure ◽  
Increasing Temperature ◽  
Arrhenius Temperature

<p>This thesis is concerned with the measurement and interpretation of electrical conductivity in molten silicates. Physicochemical properties and structural models of silica and silicates are reviewed first, to give a general picture of their behaviour. Electrical conductivity was measured as a function of temperature, pressure and water composition. To make these measurements an internally heated pressure vessel, designed to operate at temperatures up to 1200 degrees C and pressures up to 5 kbars was constructed. Conductivity measurements were made on the following anhydrous and hydrous silicate melts: SiO2/Na2O 60/40, 65/35, 75/25, 78/22 mol%; SiO2/Na2O/CaO 72/24/4 mol%; Mt. Erebus lava; SiO2/Na2O 78/22 mol% + ~5 wt% H2O and Mt. Erebus lava + ~4 wt% H2O in the temperature range 850-1000 degrees C and the pressure range 0-1.3 kbar. Arrhenius temperature and pressure dependencies on conductivity were observed. The pressure coefficient of conductivity was zero for the anhydrous melts well above Tg but small and positive for the hydrous silicates. Water caused ~40% reduction in conductivity when added to a melt which was accounted for in terms of the mixed alkali effect. Conductivity isobars for the hydrous silicates passed through a maximum as a function of increasing temperature. The conductivity behaviour as a function of temperature and pressure is analogous to that observed in partially ionised liquids and is intrepretated in an identical way. The range of operation of a piezoelectric alpha-quartz crystal viscometer was extended to allow measurement of viscosity as a function of temperature.</p>

Electrical conductance of a mixture of sodium and potassium nitrates in aqueous medium

1990 ◽  
Vol 68 (11) ◽  
pp. 2115-2118 ◽  
Author(s):  
Ratan Lal Gupta ◽  
Kochi Ismail
Keyword(s):  
Aqueous Medium ◽  
Electrical Conductance ◽  
Potassium Nitrate ◽  
Molar Conductance ◽  
Size Parameter ◽  
Mixed Alkali ◽  
Mixed Alkali Effect ◽  
The Difference ◽  
Ion Size ◽  
Sodium And Potassium

Electrical conductance and density measurements of [xNaNO3 + (1 − x)KNO3] + RH2O system were taken as functions of x, R, and temperature. The mixed alkali effect on molar conductance (Λ) was found to be negligible upto R = 25 and becomes significant in the region where R < 25. It has been shown that for mixed electrolytic system in aqueous medium the concentration range at which the mixed alkali effect on Λ starts becoming significant can be predetermined by plotting the difference in Λ of the two pure electrolytic solutions versus R. The concentration dependence of Λ has been described satisfactorily by the expression Λ = ΛFLK exp (Bc + Cc2) where ΛFLK is the Falkenhagen–Leist–Kelbg equation for Λ, B and C are empirical constants, and c is the molar concentration. The observed values of the ion-size parameter have indicated more ionic association in KNO3 solution than in NaNO3 solution. Keywords: electrical conductance, sodium nitrate, potassium nitrate, mixed alkali effect.

scholarly journals The Electrical Conductivity of Some Hydrous and Anhydrous Molten Silicates as a Function of Temperature and Pressure

2021 ◽  
Author(s):  
◽  
John Satherley
Keyword(s):  
Electrical Conductivity ◽  
Quartz Crystal ◽  
Pressure Coefficient ◽  
General Picture ◽  
Water Composition ◽  
Mixed Alkali ◽  
Mixed Alkali Effect ◽  
Temperature And Pressure ◽  
Increasing Temperature ◽  
Arrhenius Temperature

<p>This thesis is concerned with the measurement and interpretation of electrical conductivity in molten silicates. Physicochemical properties and structural models of silica and silicates are reviewed first, to give a general picture of their behaviour. Electrical conductivity was measured as a function of temperature, pressure and water composition. To make these measurements an internally heated pressure vessel, designed to operate at temperatures up to 1200 degrees C and pressures up to 5 kbars was constructed. Conductivity measurements were made on the following anhydrous and hydrous silicate melts: SiO2/Na2O 60/40, 65/35, 75/25, 78/22 mol%; SiO2/Na2O/CaO 72/24/4 mol%; Mt. Erebus lava; SiO2/Na2O 78/22 mol% + ~5 wt% H2O and Mt. Erebus lava + ~4 wt% H2O in the temperature range 850-1000 degrees C and the pressure range 0-1.3 kbar. Arrhenius temperature and pressure dependencies on conductivity were observed. The pressure coefficient of conductivity was zero for the anhydrous melts well above Tg but small and positive for the hydrous silicates. Water caused ~40% reduction in conductivity when added to a melt which was accounted for in terms of the mixed alkali effect. Conductivity isobars for the hydrous silicates passed through a maximum as a function of increasing temperature. The conductivity behaviour as a function of temperature and pressure is analogous to that observed in partially ionised liquids and is intrepretated in an identical way. The range of operation of a piezoelectric alpha-quartz crystal viscometer was extended to allow measurement of viscosity as a function of temperature.</p>

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