How many moles are in a pill containing 37.0mg of c12h22feo14

From the periodic table:
mass of carbon = 12 grams
mass of hydrogen = 1 gram
mass of iron = 55.84 grams
mass of oxygen = 16 grams
Therefore:
molar mass of C12H22FeO14 = 12(12) + 22(1) + 55.84 + 14(16) = 445.84 grams

number of moles = mass / molar mass
number of moles = 0.037 / 445.84 = 82.989 x 10^-6 moles

8.29 x 10^-5 moles. First lookup the atomic weights of all involved elements. Atomic weight carbon = 12.0107 Atomic weight hydrogen = 1.00794 Atomic weight iron = 55.845 Atomic weight oxygen = 15.999 Now calculate the molar mass 12 * 12.0107 + 22 * 1.00794 + 55.845 + 14 * 15.999 = 446.13408 g/mol Finally divide the mass by the molar mass to get the number of moles. Remember to convert the mass to grams. .0370 g / 446.13408 g/mol = 0.0000829347 moles Since 0.0000829347 is a rather inconvenient number to deal with, convert to scientific notation and round to 3 significant figures since that's the precision of the data we have. So the answer is: 8.29 x 10^-5 moles.

The answer is c. valence electrons