Amysterious white powder is found at a crime scene. a simple chemical analysis concludes that the powder is a mixture of sugar and morphine (c17h19no3), a weak base similar to ammonia. the crime lab takes 10.00 mg of the mysterious white powder, dissolves it in 100.00 ml water, and titrates it to the equivalence point with 2.84 ml of a standard 0.0100 m hcl solution. what is the percentage of morphine in the white powder?

81.0% Calculate the number of moles of hcl used. 0.00284 l * 0.0100 = 0.0000284 mol = 2.84 x 10^-5 mol Now calculate the molar mass of C17H19NO3. First, lookup the atomic weights of the involved elements. Atomic weight carbon = 12.0107 Atomic weight hydrogen = 1.00794 Atomic weight nitrogen = 14.0067 Atomic weight oxygen = 15.999 Molar mass = 17 * 12.0107 + 19 * 1.00794 + 14.0067 + 3 * 15.999 = 285.33646 g/mol Now determine the mass of 2.84 x 10^-5 moles of the substance. 2.84 x 10^-5 mol * 285.33646 g/mol = 0.008103555 g = 8.10 mg Finally, divide the now known mass of morphine by the mass of the sample, so 8.10 mg / 10.00 mg = 0.810 = 81.0%