1. Find the molar mass of water:
* H₂O has two hydrogen atoms (1.01 g/mol each) and one oxygen atom (16.00 g/mol).
* Molar mass of H₂O = (2 * 1.01 g/mol) + (16.00 g/mol) = 18.02 g/mol
2. Convert grams to moles:
* moles = mass / molar mass
* moles = 16.75 g / 18.02 g/mol
* moles ≈ 0.93 mol
3. Use Avogadro's number:
* Avogadro's number states that there are 6.022 x 10²³ molecules in one mole of any substance.
* Number of molecules = moles * Avogadro's number
* Number of molecules ≈ 0.93 mol * 6.022 x 10²³ molecules/mol
* Number of molecules ≈ 5.60 x 10²³ molecules
Therefore, there are approximately 5.60 x 10²³ molecules in 16.75 grams of water.
