Question

Acetaminophen found in Tylenol belongs to a class of drugs called analgesics (pain relievers) and antipyretics (fever reducers). The molecularformula for acetaminophen is CgHgNO2.a) What is the mass of 30 molecules of acetaminophen, if the nfass of carbon, hydrogen, nitrogen and oxygen are 12.01 amu/atom, 1.008 amu/atom,14.01 amu/atom, and 16.00 amu/atom respectively? Round to the nearest tenth if necessary.b) What is the unit symbol for your answer?1

Answer 1

We have acetaminophen (molecular formula: C8H9NO2)

1) First, let's calculate the molar mass for this molecule

The molar mass C8H9NO2 = 12.01 amu/atom x 8 atoms + 1.008 amu/atom x 9 atoms + 14.01 amu/atom x 1 + 16.00 amu/atom x 2 = 151.2 amu (uma is for atoms, atomic mass unit)

We express this result as grams, 151.2 g/mol

We know Avogadro's number says,

1 mol C8H9NO2 = 151.2 g = 6.022x10^23 formula units (atoms, molecules, ions, etc)

So,

151.2 g --------- 6.022x10^23 molecules

x --------- 30 molecules

x = 7.532x10^-21 g

b) Units = g

Answer: 7.532x10^-21 g