Nalorphene `(C_(19)H_(22)NO_(3))`, similar to morphine , is used to combat withdrawal symptoms in narcotic users. The dose of nalorphene generally given is `1.5 mg`. Calculate the mass of solution of `1.5xx10^(-3)m` aqueous solution required for the above dose.

Explanation

`1.5xx10^(-3)` m aqueous solution of nalorphene means that `1.5xx10^(-3)` mole of nalorphene is dissolved in 1 kig of water.
Molar mass of nalorphene, `C_(19)H_(21)NO_(3)`
`=19xx12+21+14+3xx16=311 " g mol"^(-1)`
` therefore 1.5xx10^(-3)` mole of nalorphene
`=1.5xx10^(-3)xx311 g=0.467 g`
`therefore` Mass of solution `=0.467+1000=1000.467 g`.
For 0.467 g of nalorphene, mass of solution required =1000.467 g
For 1.5 mg `(1.5xx10^(-3)g)` of nalorphene, mass of solution required
`=(1000.467)/(0.467)xx1.5xx10^(-3)=3.21 g`.