Abstract:
The study of structure of water and of aqueous solutions of electrolytes and
non-electrolytes are important from both theoretical and practical points of
view. Water structure plays an important role in aqueous systems. The
knowledge of water structure is a prerequisite to understand the various
interactions in the aqueous solutions. In this investigation, the experimental
measurements of density and viscosity of aqueous solution of FeCI3• CoCh,
CuCh, MgClz, HgCh and NiCh (electrolytes) in the presence of methanol
and ethanol were carried out at different temperature (S-3S°C). Here, some
parameters related to density and viscosity, such as B-coefficients of Jones-
Dole equation, excess molar volume VmE, apparent molal volumes, enthalpy
of activation ~H'1#'free energy of activation ~G'1#and entropy of activation,
T~S'1#for viscous flow were calculated by using standard equation in order
to investigate the effect of methanol and ethanol on the structure modifying
properties ofFeCh. CoCh, CuClz,MgCJz,HgClz and NiCh (electrolytes) on
water. In this study the values apparent molar volumes of all solutions are
found positive and increase almost linearly with increase mole fraction of
electrolytes both in methanol-water and ethanol-water system. The
experimentally determined viscosity values of different solutions were found
to decrease with increase of temperature. The positive values of Bcoefficient
for the solution containing trivalent cation such as Fe3
+, C03
+
were observed higher than those of bivalent cation such as Mg
z
+, Cu
z
+ etc.
The positive values indicate that the electrolytic salts taken in this study are
structure maker. The structure intensifying properties of these electrolytes
were also supported by the calculated values of thermodynamic quantities
such as ~H'1#'~G'1#and T~S'1#'
