# What is the molality of acetone in a solution composed of 255 g of acetone, (CH_3)_2CO, dissolved in 200 g of water?

Apr 28, 2016

$\text{Molality}$ $=$ $\text{Moles of solute"/"Kilograms of solvent}$. Here we consider acetone to be the $\text{solute}$.
Given that definition, and also that the molar mass of acetone is $58.08 \cdot g \cdot m o {l}^{-} 1$, we can calculate the molality of the solution.
$\text{Molality}$ $=$ $\frac{255 \cdot \cancel{g}}{58.08 \cdot \cancel{g} \cdot m o {l}^{-} 1}$ $\times$ 1/(200*cancelgxx10^-3*kg*cancel(g^-1)
$=$ ??*mol*kg^-1.