139. Solving a chemistry problem

138. For the chromatographic determination of nickel on paper impregnated with a solution of dimethylglyoxime, three standard solutions were prepared. A weighed portion of NiCl2 • 6H2O weighing m (g) was dissolved in a volumetric flask with a capacity of 50.0 ml. To build a calibration graph 5.00; 10.00 and 20.00 ml of the resulting solution was diluted with water to 50.0 ml. The analyzed solution containing nickel was also diluted with water to 50.0 ml and the height of the peaks formed during chromatography was measured. Determine the mass (mg) of nickel in the test solution. Table;

m, g Peak height, mm
h1 h2 h3 hX
0.2040 21.0 38.5 72.3 43.3