Concentration determination by means of refractometric
method: A consequent dilution of an unknown binary
aqueous solution
Accepted 22nd September,
2020
Mihai Petrov
Department of Real Sciences, section of Physics
and Mathematics, University "Prof. Asen Zlatarov",
Burgas City, Republic of Bulgaria.
The physics-chemical methods of the study are
important means of determining the parameters of
the researched samples. One of the
physics-chemical and in particular optical
methods is the refractometric method, which is
based on determining the concentrations of the
transparent solutions by the measurements of the
refractive indexes with technical tools called
refractometers. The current situation of the
refractometric method is based on the method of
standard solutions with known concentrations of
the known substance and only the case when the
calibration graph is presented then it allows
determining the unknown concentration of the
investigated solution. The present study
proposes a method based on the consequent
dilution of the researched binary solution
without using any of the standards. A binary
solution is a system that consists of two parts:
the dissolved substance and the solvent. A part
of the volume of the solution is separated into
a separate vessel from the given sample of this
solution with unknown concentration, and the
mass of the separated solution is measured. The
initial unknown concentration of the researched
solution is the same as for the separated
volume. The refractive indexes are measured
after each consequent dilution by the addition
of the solvent with the same volumes of 2 ml.
Finally, the measured data of the refractive
indices allow to calculate by the proposed
formula in the paper the unknown concentration
of the unknown substance of this binary
solution. The value of the calculated
concentration of the unknown substance is used
for further calculating the concentrations of
the consecutively diluted solutions. These
values of the concentrations finally allow to
represent the graph of the refractive indices as
the function of the diluted concentrations which
validate principly the linearity of the
refractive indices as the function of the
concentration. Another specific method of mass
refractive solvent factor is suggested and
performed in this study for the determination of
unknown concentration. All the researches are
performed at usual room temperature.
This is an open access article
published under the terms of the
Creative Commons Attribution
License, which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is
properly cited.
Cite this article as:
Petrov M (2021). Concentration determination by
means of refractometric method: A consequent dilution of an unknown binary
aqueous solution. Acad. J. Sci. Res. 9(1): 009-018.
