1.
If 4.10 g of copper react with oxygen gas form 5.03 g of copper
oxide,
a) What was the mass of oxygen gas that combined with the
copper? (hint: the law of conservation of mass applies here.)
b) Calculate the number of moles of copper that reached
c) Calculate the number of moles of oxygen that reacted
d) What is the empirical formula for this compound?
2.
The stimulant caffeine is comprised of four elements: carbon,
hydrogen, nitrogen, and oxygen. Given the following % composition,
determine the empirical formula of caffeine.
49.48% C
5.19% H
28.85% N
16.45% O