Here's how to calculate the number of moles of oxygen atoms in 18.1 moles of CH2O:

1. Identify the Mole Ratio:

* In one molecule of CH2O, there is one oxygen atom.

2. Apply the Mole Ratio:

* Since there's a 1:1 ratio of CH2O molecules to oxygen atoms, 18.1 moles of CH2O will contain 18.1 moles of oxygen atoms.

Therefore, there are 18.1 moles of oxygen atoms in 18.1 moles of CH2O.