Caffeine has the following percent composition: carbon 49.48%, hydrogen 5.19%, oxygen 16.48% and nitrogen 28.85%. Its molecular weight is 194.19 g/mol. Determine the empirical and molecular formulas.

If 90.0 grams of ethane reacted with excess chlorine,how many grams of dicarbon hexachloride would form

What is the percentage composition of carbon in the compound ch4

What is a substance? a. a physical property of matter b. a chemical property of matter c. an element or compound that cannot be physically separated d. characteristics used to tell the difference between mixtures