1. Find the molar mass of H2O:

* H (hydrogen) has a molar mass of 1.008 g/mol

* O (oxygen) has a molar mass of 15.999 g/mol

* Molar mass of H2O = (2 * 1.008 g/mol) + 15.999 g/mol = 18.015 g/mol

2. Use the formula:

* moles = mass / molar mass

3. Calculate:

* moles = 7.038 g / 18.015 g/mol

* moles ≈ 0.391 mol

Therefore, there are approximately 0.391 moles of H2O in 7.038 grams of H2O.