Question

what is the percentage of ethanol in a sample of 1.78g glacial acetic acid

Answer 1

To answer this questuon one should know the mass of ethanol in a sample of glacial acetic acid.

For example if $m(C_2H_5OH) =0.05 g$

Then $w(C_2H_5OH) = \frac{0.05g}{1.78 g} = 0.028$