Question: how many molecules are in 2.00 moles of h2o?
Answer: If you have a compound like H2O, then: one mole of water contains 6.02 x 1023 MOLECULES of water. But each molecule of water contains 2 H and 1 O atom = 3 atoms, so there are approximately 1.8 x 1024 atoms in a mole of water.