# Calculation of Molecular formulas

1. What is the % composition of CuS?

2. How many Lithium atoms are in 1.43g of LiO?

3. What is the Empirical Formula if the % composition is 68.8% C, 5.0% H, and 26.2% O? If MW of the real formula is 244g/mL, what is the actual formula?