141. Solving a chemistry problem

When determining zirconium by the fluorescence of zirconium-morin
complex after fusion of 0.25 g of ore with soda and leaching of the melt
water to the solution was added 6 M HCl and the volume was brought to 25.00 ml. Into dimensional
a flask with a capacity of 25.00 ml, 2.00 ml of the analyzed solution was taken,
added thioglycolic acid to reduce Fe (III),
concentrated HC1, an alcoholic solution of morin and brought with water to
labels. In the same way, a standard solution was prepared with
containing 2 μg of zirconium in 25.00 ml. Measured the intensity
fluorescence of these solutions: 1x1 = 35 and 1d = 70. In the analyzed and
the same weighed amount of EDTA - quencher was dissolved in standard solutions
fluorescence of only the zirconium-morin complex and re-measured
fluorescence intensities of solutions 1x2 = 3.0 and 12 = 4.0. Calculate
mass fraction (%) of zirconium in ore