1. Determine the molar mass for Li, S (Show all work).

If you refer to your periodic table, the atomic weight is the molar mass of each element. The molar mass of Lithium is 6.9 g/mol and Oxygen 16.0 g/mol. the molar mass of lithium Li2O is 6.9 × 2 = 13.8 g/mol

Explanation:

KEY TAKEAWAYS FOR HOW TO FIND MOLAR MASS:

1. The mole allows scientists to calculate the number of elementary entities (usually atoms or molecules ) in a certain mass of a given substance.

2. Avogadro’s number is an absolute number: there are 6.022×1023 elementary entities in 1 mole. This can also be written as 6.022×1023 mol-1.

3. The mass of one mole of a substance is equal to that substance’s molecular weight. For example, the mean molecular weight of water is 18.015 atomic mass units (amu), so one mole of water weight 18.015 grams.

- Key Terms

mole: The amount of substance of a system that contains as many elementary entities as there are atoms in 12 g of carbon-12.