Concentrations: molality and molar fraction

Tutorial 2

        

Use this schematic "lattice" and →    définitions to resolve the following exercise:

Exercise Calculate the molar fraction of a solution of ethanol in water of molarity $2,00\frac{mol}{kg} $! Solution (Click): Scheme and formulas: .......... Calculation: ..........$1000\; g$ d'eau (le solvant) renferment $2,00\; mol$ d'éthanol
$n_{sl}= \frac{m_{sl}}{M_{sl}}$ = $\frac{1000}{18} = 55,56\; mol$
$X_{so}= \frac{n_{so}}{n_{so}+n_{sl}}$=$\frac{2,00}{2,00+55,56}=0,0347$