To reveal the concentration-dependent optical properties of aqueous, ethanol
and toluene binary solutions, the refractometry method was used. The peak of
refractive indices corresponds to formed heteromolecular complexes with a certain
concentration. The bonds between the molecules formed in mixtures are also directly
related to their chemical structure. The bonds that form between polar and non-polar
compounds and also between polar protic and polar aprotic compounds are different.
All solutions were measured in the concentration range ~0÷1 mole fraction at room
temperature. In our work, we have shown that, along with Infrared and Raman
spectroscopy, the refractometric method is effective for the determination of formed
structures in mixtures.