Question

The density of a $60.00\mathrm{\%}$ (m/m) ethanol, ($C_2{H}_{5}OH$) solution is $0.8937\mathrm{gm}{\mathrm{ml}}^{-1}$ what is the molarity of the solution?

Answer 1

Step 1: Given data

Density of ethanol$=0.8937\mathrm{gm}{\mathrm{ml}}^{-1}$

The weight percentage of ethanol$=60\%$

Step 2: Calculating molarity

Applying the formula which relates molarity, weight percentage, and density.

$\mathrm{M}=\frac{\%\mathrm{w}/\mathrm{w}\times \mathrm{d}\times 10}{\mathrm{Molecular}\mathrm{weight}}$

The molecular weight of ethanol$=46.07\mathrm{g}$

Substituting the values we get,

$\mathrm{M}=\frac{60\times 0.8937\times 10}{46.07}\Rightarrow 11.63\mathrm{mol}{\mathrm{L}}^{-1}$

Therefore, the molarity of the solution is $11.63\mathrm{mol}{\mathrm{L}}^{-1}$