707(3). For the luminescent determination of boron in ore, sample a was dissolved and, after appropriate treatment, the volume of the solution was brought to 100.0 ml. Then an alcoholic 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 per 100 ml. After adding the same reagents and in the same quantities to 1.00 ml of each standard solution as in the case of the test solution, their luminescence intensity turned out to be 0.38; 0.65 and 1.08 respectively. Construct a calibration graph and determine the percentage of boron in the ore:
Ore weight a, g 0.1750
IX 0.52

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