A solution of glycerol `(C_(3)H_(8)O_(3))` in water was prepared by dissolving some glycerol in `500g` of water. This solution has a
boiling point of `100.42^(@)C` while pure water boils at `100^(@)C`. What mass of glycerol was dissolved to make the solution ?
(`K_(b)` for water `= 0.512 K kg mol^(-1)`)
boiling point of `100.42^(@)C` while pure water boils at `100^(@)C`. What mass of glycerol was dissolved to make the solution ?
(`K_(b)` for water `= 0.512 K kg mol^(-1)`)
`W_(H_(2)O) = 500 g = 0.5 kg, T_(b)^(0) = 100^(0)CW_(“glycerol”)`
`:. T_(b) = 100.42 .^(@)C`.
`DeltaT_(b) = 0.42.^(@)C`
`DeltaT_(b) = K_(bm)`
`DeltaT_(b) = (W_(“glycerol”))/(W_(H_(2)O) xx M_(“glycerol”))`
`0.42 = 0.512 xx (W_(“glycerol”))/(0.5 xx 92)`
`W_(“glycerol”) = (0.42 xx 0.5 xx 92)/(0.512) = 37.73 g`.