Sodium diethyldithiocarbamate, limiting equivalent conductance (Λ0), ion association, activation energy and thermodynamic functions.
Introduction:
The measurement of electrical conductivities of dilute solutions of salts or complexes is considered to be one of the important methods for studying the ion-pair or multiple- ion association not only in aqueous solutions but also in non-aqueous or mixed ones 1-4. Also, conductivity measurements were used to evaluate the hydration free energy of some electrolytic solutions and to study the nature of the solute-solvent interaction 5. The present work aims to determine the conductance values of sodium diethyldithiocarbamate (NaDDC) which have been measured in water at different temperatures (25, 30, …show more content…
this value was obtained from the computer reading, where J is being a function of a° and has the following equation 31:
J = σ1 Λo + σ2 (3)
Where σ1 and σ2 are the functions of J. The derived constants are represented in Table 3. It can be seen from Table 3, that Λo values increase with increasing the temperature. The values of KA increase with increasing the temperature where the dielectric constant of solvents decreases with increasing the temperature as reported in literature (28-30) thus, Ion association occurs. The trend of KA in the present work was explained in the light of the U term as represented in the following equation 32: ln KA = ln (4 π NA ao 3 /3000) + e2 / aoDkT + U (4)
Where U = ΔS / k – Es / kT (5)
ΔS / k is the entropy Boltzman constant ratio which illustrates the probability of the orientation of the solvent molecules around the free ions and Es / kT is an energy relationship which includes the energy of the solvent molecules with respect to the free ions and ion-pairs. In case of water in Table 4 the U term increases with increasing the temperature, i.e. the entropy term is more predominant than ion–dipole term for sodium
Introduction:
The measurement of electrical conductivities of dilute solutions of salts or complexes is considered to be one of the important methods for studying the ion-pair or multiple- ion association not only in aqueous solutions but also in non-aqueous or mixed ones 1-4. Also, conductivity measurements were used to evaluate the hydration free energy of some electrolytic solutions and to study the nature of the solute-solvent interaction 5. The present work aims to determine the conductance values of sodium diethyldithiocarbamate (NaDDC) which have been measured in water at different temperatures (25, 30, …show more content…
this value was obtained from the computer reading, where J is being a function of a° and has the following equation 31:
J = σ1 Λo + σ2 (3)
Where σ1 and σ2 are the functions of J. The derived constants are represented in Table 3. It can be seen from Table 3, that Λo values increase with increasing the temperature. The values of KA increase with increasing the temperature where the dielectric constant of solvents decreases with increasing the temperature as reported in literature (28-30) thus, Ion association occurs. The trend of KA in the present work was explained in the light of the U term as represented in the following equation 32: ln KA = ln (4 π NA ao 3 /3000) + e2 / aoDkT + U (4)
Where U = ΔS / k – Es / kT (5)
ΔS / k is the entropy Boltzman constant ratio which illustrates the probability of the orientation of the solvent molecules around the free ions and Es / kT is an energy relationship which includes the energy of the solvent molecules with respect to the free ions and ion-pairs. In case of water in Table 4 the U term increases with increasing the temperature, i.e. the entropy term is more predominant than ion–dipole term for sodium