Question: how many oxygen atoms are found in one molecule of nitric acid hno3?
Answer: nitric acid, then 120 g contains 81.6 g of HNO3 and 38.4 g of water. This gives you (81.6 / 63.01) = 1.295 moles of HNO3 and (38.4 / 18.02) = 2.131 moles of water. Each mole of HNO3 contains 6.02 x 1023 molecules each containing an oxygen atom.