Question

What is the molality of an aqueous solution of ethyl alcohol $(C{H}_{3}C{H}_{2}OH,molarmass=46.0gmo{l}^{-1})$ which contains 50.0 g of alcohol in 500 mL of the solution

Answer 1

Mass of ethyl alcohol/litre
$=\frac{50\times 1000}{500}=100g$
No. of moles of alcohol/litre
$=\frac{\left(Massing/litre\right)}{Molarmassing/mol}$
$=\frac{100}{46}=2.18$
Thus, the solution contains 2.18 moles of ethyl alcohol per litre of the solution.
So, the molarity of the solution is 2.18 mol/L.