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 × 10-3 m aqueous solution required for the above dose.

molar mass of Nalorphene = 311g/mol

Now 1000g of solution contains 1.5 × 10-3 moles of Nalorphene(Molality of solution = moles of solute/mass of solvent(in kg))


1.5 × 10-3 moles of Nalorphene = 1.5 × 10-3 × 311 = 0.4665g of Nalorphene


Therefore, total mass of the solution = (1000 + 0.4665) g


total mass = 1000.4665 g


This implies that the mass of the solution containing 0.4665 g of nalorphene is 1000.4665 g.


Therefore, mass of the solution containing 1.5 mg of nalorphene is:



mass of solution containing required ions = 3.22 g


Hence, the mass of aqueous solution required is 3.22 g.


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