* Molar mass relates mass and moles: Molar mass tells you the mass of one mole of a substance. For example, water (H₂O) has a molar mass of 18.015 g/mol. This means 18.015 grams of water contains 1 mole of water molecules.
* You need mass to calculate moles: To find the number of moles, you need to know the mass of the sample. You can then use the following formula:
Moles (n) = Mass (m) / Molar mass (M)
Example:
If you have 36.03 grams of water (H₂O), you can calculate the moles:
* Moles = 36.03 g / 18.015 g/mol = 2 moles
In summary:
* Molar mass alone doesn't tell you the number of moles.
* You need both the mass of the compound and its molar mass to calculate the number of moles.
