# A 17.2*g mass of ethylene glycol was dissolved in a 500*g mass of water to give a solution of 515*mL volume. What are....?

## $\text{(i) Molarity...}$ $\text{(ii) Molality...}$ $\text{(iii) Percentage by mass...}$ $\text{(iv) Moles fractions of each component...}$

Feb 2, 2017

$\text{Moles of solute}$ $=$ $\frac{17.2 \cdot g}{62.07 \cdot g \cdot m o {l}^{-} 1} = 0.277 \cdot m o l$

#### Explanation:

$\text{Molarity"="Moles of solute"/"Volume of solution} = \frac{0.277 \cdot m o l}{0.515 \cdot L}$

$\cong 0.50 \cdot m o l \cdot {L}^{-} 1$

$\text{Molality"="Moles of solute"/"Kilograms of solvent} = \frac{0.277 \cdot m o l}{0.500 \cdot k g}$

$\cong 0.50 \cdot m o l \cdot k {g}^{-} 1$

$\text{Percentage by mass}$ $=$ "Mass of solute"/"Mass of solution"xx100%

=(17.2*g)/(17.2*g+500*g)xx100%=3.33%(m/m)

$\text{Mole fraction, "chi_"diol}$ $=$ $\text{Moles of diol"/"Moles of diol + moles of solvent}$

$= \frac{0.277 \cdot m o l}{0.277 \cdot m o l + \frac{500 \cdot g}{18.01 \cdot g \cdot m o {l}^{-} 1}} \cong 0.001$

What is ${\chi}_{\text{water}}$?