what is the percent by mass of oxygen in propanal, CH3CH2CHO?
the answer is 27.6 %. but i need to know why, please help !
1 answer
The molecular weight of propanal is 58.08 g/mol. Oxygen has an atomic weight of 16 g/mol, so the mass of oxygen in propanal is 16 g/mol x 1 mol/58.08 g = 0.276 g/mol. The percent by mass of oxygen in propanal is 0.276 g/mol x 100%/58.08 g/mol = 27.6%.
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