189. When determining lead in ethyl alcohol, the analyzed solution of mass m (g) was evaporated, the dry residue was dissolved in hydrochloric acid and the intensity of the luminescence burst was measured when the solution (Ix) was defrosted. Under similar conditions, a burst of luminescence of standard solutions of lead (I) was registered. A weighing of lead weighing 0.1020 g was dissolved in concentrated HCl and the volume of the solution was brought to 100 ml: 1.00 ml of this solution was diluted to 100 ml (solution A). Then in volumetric flasks with a capacity of 100 ml made: 0; 0.1; 0.2; 0.3; 0.4; 0.5 ml of solution A, brought to the mark and obtained for standard solutions the following values I: 11, 20, 29, 40, 49. Calculate the mass fraction (%) of lead in alcohol, if 1 ml of solution was added to the cuvette for measurements and received the following data Ix:
Task number 189
m, mg 1.034
Ix, scale divisions 24

If you do not open the file - install the RAR archiver. Inside the archive you will find a solution in Word format.