64. Solving a chemistry problem

1. For the luminescent determination of aluminum in hydrochloric acid, a sample of 0.1500 g of it was evaporated, the residue was dissolved and 500 cm3 of solution was obtained. 50 cm3 of it was transferred to a volumetric flask with a capacity of 100 cm3, acid chromium-blue-black was added and brought to the mark with distilled water. The fluorescence intensity of the obtained solution was 60. The intensity of the standard solution containing 30 μg of aluminum in 100 cm3 was 86. Calculate the mass fraction of aluminum in the test sample if the luminescence intensity of the blank solutions is 10.