Solving a chemistry problem 000 001

2. To determine folic acid, the polarography method was used. In volumetric flasks with a capacity of 50 ml, standard solutions with different precisely known concentrations of folic acid were prepared, polarograms of these solutions were taken, and for each solution the height h of the polarographic wave was measured, corresponding to the diffusion current of folic acid:
C(FC), mg/ml 0.15 0.25 0.35 0.45
h, mm 56 94 134 172
An aliquot of the test solution with a volume of Va = 7.0 ml was taken into a 50 ml volumetric flask, the corresponding background electrolyte was added, diluted with water to the mark and the test solution was obtained. Under the same conditions in which the polarography of standard solutions was carried out, a polarogram of the test solution was taken and the height h of the wave was measured - 106 mm. Construct a calibration graph in coordinates h, mm – C(FC), mg/ml and, using the data given below, determine the concentration (mg/ml) of folic acid in the analyzed solution.
Draw a schematic polarogram and show how the wave height is found graphically. Name and indicate in the figure the parameter used to identify a substance using the polarographic method.