Theme 4- EXPERIMENTAL PROCEDURE REFRACTOMETRICAL METHOD OF DETERMINATION OF AQUEOUS SOLUTIONS OF NATRIUM CHLORIDE AND OF THE BLOOD SAMPLES

Question 1

1) The representation of the standard curve for the standard solutions of natrium chloride

Answer 1

-The molar concentration values measured in mol/l is applied to plot a standard curve for sodium chloride standard solutions.
-There are concentrations Cm which are measured in g/l.
-The following relation exists between the percentage concentrations C% of solutions and
the concentrations in g/l:
Cm = 10 x C%
-The following relation exists between molar concentrations of C measured in mol/l and concentrations of Cm:
Cm = M x C
; where M is the molar mass.
-There is the following expression between molar concentrations C and the C%
C= 10xC%/M

Question 2

2. The determination of the unknown concentration of aqueous solutions of Natrium
   chloride

Answer 2

-Having the standard curve for the standard solutions of sodium chloride, the unknown
concentration Cx % can be found
-The refractive index nx is measured with the refractometer and the point of intersection with the standard line allows the value C x% to be read.