Acetaminophen (pictured) is a popular nonaspirin, "over-the-counter" pain reliever. what is the mass % (calculate to 4 significant figures) of each element in acetaminophen?

Acetaminophen as a chemical formula of C8H9NO2. The molar masses are:

C8H9NO2 = 151.163 g/mol

C = 12 g/mol

H = 1 g/mol

N = 14 g/mol

O = 16 g/mol

TO get the mass percent, simply multiply the molar mass of each elements  with the number of the element divide by the molar mass of acetaminophen, that is:

%C = [(12 * 8) / 151.163] * 100% = 63.50%

%H = [(1 * 9) / 151.163] * 100% = 5.954%

%N = [(14 * 1) / 151.163] * 100% = 9.262%

%O = [(16 * 2) / 151.163] * 100% = 21.17%