What is the percent by mass of oxygen in propanal, ch3ch2cho? (1) 10.0% (3) 38.1%
(2) 27.6% (4) 62.1%

Answer : The percent by mass of oxygen in propanal is, 27.58 %

Solution : Given,

Molar mass of carbon = 12 g/mole

Molar mass of hydrogen = 1 g/mole

Molar mass of oxygen = 16 g/mole

First we have to calculate the molar mass of propanal,

Molar mass of propanal, =

Now we have to calculate the percent by mass of oxygen in propanal.

Therefore, the percent by mass of oxygen in propanal is, 27.58 %

i dont know the answe

a is the correct answer