Molarity = moles of solute / kg solvent
Assume you have exactly 1 kg of solution. 70% of that, or 700
grams of the solution is C2H6O2, and 300 g of the solution is water.
Moles C2H6O2 = 700 g / 62.07 g/mol = 11.28 mol C2H6O2
molarity = 11.28 mol / 0.3 kg H2O = 37.59 molal
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Molarity = moles of solute/L of solution
there is 1 kg of solution has a volume of:
1000 g / 1.05 g/mL = 952 mL = 0.952 L
Molarity = 11.28 mol / 0.952 L = 11.85 M
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Mole fraction ethylene glycol = moles ethylene glycol /
(moles ethylene glycol + moles H2O)
moles ethylene glycol = 11.28
moles H2O = 300 g / 18.0 g/mol = 16.67 mol H2O
mole fraction = 11.28 /( 11.28 + 16.67) = 0.404
