Question

An antifreeze solution is prepared from `222.6 g` of ethylene glycol `[C_(2)H_(4)(OH)_(2)]` and `200 g` of water. Calculate the molality of the solution. If the density of the solution is `1.072g mL^(-1)` then what shall be the molarity of the solution?

Answer 1

Correct Answer - `a m=17.95, b. M=9.1`
`Mw` of ethylene glycol `=62g`
`a.` `m=(W_(2)xx1000)/(Mw_(2)xxW_(1))=(222.6xx1000)/(62xx200)=17.95mol Kg^(-1)`
`b.` Weight of solution `=222.6+ 200=422.6g`
`d_(sol)=1.072 g mL^(-1)`
Volume of solution `=(422.6)/(1.072)=394.21mL`
`M=(W_(2)xx1000)/(Mw_(2)xxV_(sol))=(222.6xx1000)/(62xx394.21)=9.1M`