How many moles of atoms are in a 18.02E2 gram sample of water? Answer in exponential notation.

Answer 1

Use dimensional analysis and the following conversions:

1 mol H2O = 18 g

1 mol H2O = 6.022x1023 molecules

1 molecule of H2O has 3 atoms (2 hydrogens and 1 oxygen)

18.02x10² g x 1 mol /18 g x 6.022x10²³ molecules/mol x 3 atoms/molecule = 1.81x10²⁶ atoms