1. Convert grams to moles:
* The molar mass of water (H₂O) is approximately 18 g/mol (1 g/mol for hydrogen x 2 + 16 g/mol for oxygen).
* Divide the mass of water by its molar mass: 3 g / 18 g/mol = 0.167 moles
2. Use Avogadro's Number:
* Avogadro's number tells us there are 6.022 x 10²³ molecules in one mole of any substance.
* Multiply the number of moles by Avogadro's number: 0.167 moles * 6.022 x 10²³ molecules/mol ≈ 1.01 x 10²³ molecules
Therefore, there are approximately 1.01 x 10²³ molecules of water in 3 grams of water.
