question_answer 41)

Nalorphene (C19H21NO3), similar to morphine, is used to combat withdrawal symptoms in narcotic users. Dose of nalorphene generally given is 1.5 mg. Calculate the mass of 1.5 x 10–3 m aqueous solution required for the above dose.

Answer:

1.5 x 10-3 m solution means that 1.5 x 10-3 mole of nalorphene is dissolved in 1 kg of water Molar mass of C19H21NO3 = 19 x 12 + 21 + 14 + 48 = 311 g mol?1    1.5 x 10-3 mole of C19H21NO3 = 1.5 x 10?3 x 311 g = 0.466g = 466 mg Mass of solution = Mass of solvent + Mass of solute = 1000 g + 0466 g = 1000.466 g Thus, for 466 mg of nalorphene, solution required = 1000.466 g For 1.5 mg of nalorphene, solution required