Determine the number of atoms of O in 10.0 g of C₂H₆O₂.

Answer 1

molar mass C₂H₆O₂ = 62.07 g / mol

10.0 g x 1 mol / 62.07 g = 0.1611 mols C₂H₆O₂

0.1611 mols C₂H₆O₂ x 2 mols O / mol C₂H₆O₂ = 0.3222 mols O

0.3222 mols O x 6.02x10²³ atoms / mol = 1.94x10²³ atomos of O

or ...

0.1611 mols C₂H₆O₂ x 6.02x10²³ molecules of C₂H₆O₂ / mol = 9.698x10²² molecules of C₂H₆O₂

9.698x10²² molecules of C₂H₆O₂ x 2 atoms O / molecule = 1.94x10²³ atoms of O