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

Question

$"(i) Molarity..."$
$"(ii) Molality..."$
$"(iii) Percentage by mass..."$
$"(iv) Moles fractions of each component..."$

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Answer 1 · 2017-02-02T15:42:23

$"Moles of solute"$ $=$ $(17.2*g)/(62.07*g*mol^-1)=0.277*mol$

$"Molarity"="Moles of solute"/"Volume of solution"=(0.277*mol)/(0.515*L)$

$~=0.50*mol*L^-1$

$"Molality"="Moles of solute"/"Kilograms of solvent"=(0.277*mol)/(0.500*kg)$

$~=0.50*mol*kg^-1$

$"Percentage by mass"$ $=$ $"Mass of solute"/"Mass of solution"xx100%$

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

$"Mole fraction, "chi_"diol"$ $=$ $"Moles of diol"/"Moles of diol + moles of solvent"$

$=(0.277*mol)/(0.277*mol+(500*g)/(18.01*g*mol^-1))~=0.001$

What is $chi_"water"$ ?