50. Solving a chemistry problem

200. For the luminescent determination of boron in ore, a sample of a was dissolved and, after appropriate treatment, the volume of the solution was adjusted to 100.0 ml. Then, an alcohol solution of benzoyl was added to 1.00 ml of the solution, and the luminescence intensity of the resulting solution was measured. She turned out to be IX. Standard solutions contained 4.00; 10.0 and 20.0 mg of boron in 100 ml. After addition to 1.00 ml of each standard solution of the same reagents and in the same quantities as in the case of the test solution, their luminescence intensity was 0.38; 0.65 and 1.08, respectively. Build a calibration graph and determine the percentage of boron in the ore:
Task number 200
Ore weight a, g 0.2500
IX 0.86