Calculate the mole fraction of ethanol in 95% by mass aqueous solution.Mol. mass of ethanol is 46.

1 answer

95% by mass ethanol means 95 g ethanol in 100 g total. 100 g total-5g ethanol = 95 g H2O.
mols ethanol = grams/molar mass = ?
mols H2O = grams/molar mass
total mols = mols ethanol + mols H2O
Xethanol = mol ethanol/total mols.

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