How many MOLES of oxygen are present in 3.87 grams of water ? moles.

Answer 1

Molar mass H₂O = 18.02 g / mole

moles H₂O = 3.87 g x 1 mole / 18.02 g = 0.215 moles H₂O

Each mole of H₂O contains 1 moles of O.

moles O = 0.215 moles H₂O x 1 mol O / mole H₂O = 0.215 moles O