
Pura [8], measured the conductance of ferric chloride (FeCl3 ) in primary alcohols at different temperatures. It was found that, at particular temperature ΔG0 values decrease with increase in temperature. The decrease in ΔG0 values for FeCl3 to more negative values with increasing temperature favor the transfer of the released solvent molecules into the bulk solvent and lead to a smaller ΔG0 values. The experimental values of ΔG0 for FeCl3 varied in the order: MeOH > EtOH > 1-PrOH > 1-BuOH in thetemperature range studied in this work. It was observed that ΔH0 values of FeCl3 in alcoholic organic solvents decrease in the order of MeOH > EtOH > n-PrOH > n-BuOH. ΔH0 values were found to be positive in all alcohols. Positive and high ΔH0 can be attributed to the interaction between ions. ΔS0 values of FeCl3 in primary alcohols are found to decrease in the order MeOH < EtOH < n-PrOH < n-BuOH, indicating a weakening in the ion solvation due to the formation of ion pairs. The values of ΔS0 for all alcohols used in the study were positive because of the decrease in solvation of the ion pairs compared to that of the free ions. The positive ΔS0 values for FeCl3 in all alcohols may be attributed to the increase in the degree of freedom upon association mainly due to the release of solvent molecules. In other words, the solvation of ions weakens as soon as the ion pair formation occurs. The radii of solvent molecules and the degree of solvation decreases with of -CH2- groups of primary alcohols. For that reason, higher increase in entropy is observed, and the changes of entropy become more positive values from MeOH to «-BuOH. Positive values of ΔH0 and ΔS0 values for FeCl3 can be attributed to the counter balance entropy change resulting from both short- and long- term desolvation of ions. Positive (ΔS0) values attributed to desolvation of ions are also supported by the positive enthalpy values indicating a lack of the covalent bonds [8].