Electrical Conductances of Tetrabutylammonium Bromide, Sodium Tetraphenylborate and Sodium Bromide in 2-Ethoxyethanol in the Temperature Range 35–50°C

2004 ◽  
Vol 218 (5) ◽  
pp. 599-610 ◽  
Author(s):  
Purushottam Haldar ◽  
Bijan Das
Keyword(s):  
Ion Pairs ◽  
Tetrabutylammonium Bromide ◽  
Molar Conductance ◽  
Sodium Bromide ◽  
Sodium Tetraphenylborate ◽  
Temperature Range ◽  
Electrical Conductances ◽  
Conductance Data ◽  
Limiting Molar Conductance ◽  
Concentration Equation

AbstractThe electrical conductances of the solutions of tetrabutylammonium bromide (Bu4NBr), sodium tetraphenylborate (NaPh4B) and sodium bromide (NaBr) in 2-ethoxyethanol have been reported at 35, 40, 45 and 50°C. The conductance data have been analyzed by the 1978 Fuoss conductance–concentration equation in terms of the limiting molar conductance (Λ0), the association constant (KΛ) and the association diameter (R). The ionic contributions to the limiting molar conductances (Λ0) have been estimated using the “reference electrolyte” tetrabutylammonium tetraphenylborate (Bu4NPh4B). Appreciable ionic association was observed for all of these electrolytes which were found to exist in the form of solvent-separated ion-pairs in 2-ethoxyethanol. The tetrabutylammonium and tetraphenylborate ions are found to remain scarcely solvated whereas the sodium and bromide ions undergo substantial solvation in 2-ethoxyethanol medium in the temperature range investigated here.

Conductometric Study of Some Tetraalkylammonium Bromides in 2-Ethoxyethanol in the Temperature Range 35–50 °C

2004 ◽  
Vol 218 (9) ◽  
pp. 1129-1138 ◽  
Author(s):  
Purushottam Haldar ◽  
Bijan Das
Keyword(s):  
Ion Pairs ◽  
Molar Conductance ◽  
Tetraethylammonium Bromide ◽  
Temperature Range ◽  
Tetraalkylammonium Bromide ◽  
Conductance Data ◽  
Limiting Molar Conductance ◽  
Bromide Ion ◽  
Conductometric Study ◽  
Concentration Equation

AbstractThe electrical conductances of the solutions of four tetraalkylammonium bromide salts (R4NBr), namely tetraethylammonium bromide (Et4NBr), tetrapropylammonium bromide (Pr4NBr), tetrapentylammonium bromide (Pen4NBr) and tetraheptylammonium bromide (Hep4NBr) in 2-ethoxyethanol have been reported at 35, 40, 45 and 50 °C. The conductance data have been analyzed by the 1978 Fuoss conductance–concentration equation in terms of the limiting molar conductance (Λ0), the association constant (KA) and the association diameter (R). The ionic contributions to the limiting molar conductance have also been estimated. Appreciable ionic association was observed for all of these electrolytes in 2-ethoxyethanol. The tetraalkylammonium ions (R4N+) were found to remain scarcely solvated in the present solvent medium within the temperature range investigated here. The solvation of the bromide ion in these tetraalkylammonium bromide is found to be weakened as soon as the ion-pairs are formed. An increase in the temperature results in a lower level of ion-pairing for each of these salts.

scholarly journals The Audio Frequency Conductance Study of Some Metal Succinate Salts in Aqueous Medium at Different Temperatures (Part I: Magnesium, Manganese (II), Barium and Copper Succinates)

2013 ◽  
Vol 2013 ◽  
pp. 1-10
Author(s):  
Kosrat N. Kaka ◽  
Anis A. Al-Najar ◽  
Wali M. Hamad
Keyword(s):  
Molar Conductance ◽  
Audio Frequency ◽  
Walden Product ◽  
Electrical Conductances ◽  
Conductance Data ◽  
Association Reaction ◽  
Different Temperatures ◽  
Quantitative Results ◽  
Strong Electrolytes ◽  
Modified Forms

The audio electrical conductances of aqueous solutions of magnesium, manganese II, barium, and copper succinates have been measured at various temperatures in the range of 298.15 K to 313.15 K, using an audio frequency conductance bridge. The evaluation of conductance data was carried out by minimisation technique using the theoretical equations of the complete and modified forms of Pitts (P) and Fuoss-Hsia (F-H), each a three-parameter equation, association constant (KA), molar conductance (Λm), and distance parameter (a). Quantitative results showed that these salts do not behave as “strong” electrolytes, and that their dissociations are far from complete. The abnormally low conductances of these electrolytes are not due to the presence of electrically neutral molecules but to the ion-pair formation. The Walden product values, as well as the standard thermodynamics functions (ΔH∘,ΔG∘,ΔS∘) for the association reaction at the four temperatures studied, have been evaluated.

The dissociation constant for potassium methylamide ion pairs in methylamine

1978 ◽  
Vol 56 (11) ◽  
pp. 1518-1523
Author(s):  
E. Allan Symons ◽  
J. Douglas Bonnett
Keyword(s):  
Dielectric Constant ◽  
Dissociation Constant ◽  
Lower Limit ◽  
Ion Pairs ◽  
Ion Pair ◽  
Solvent Viscosity ◽  
Temperature Range ◽  
Conductance Data ◽  
Heat Of Dissociation ◽  
Good Agreement

The limiting equivalent conductance (Λ0) and ion pair dissociation constant (Kd) have been obtained for potassium methylamide in methylamine from conductance data measured over the temperature range −55 to + 25° C. The value of Kd increases from 6.3 × 10−8 mol L−1 at the highest temperature to 9.4 × 10−7 mol L−1 at the lower limit. The results show good agreement with literature data for potassium amide in ammonia after corrections for differences in solvent viscosity and dielectric constant. The heat of dissociation is −26 kJ mol−1 above −15 °C, but decreases gradually at progressively lower temperatures as a shift occurs from tight to loose ion pair structures.

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