According to the following reaction, how many grams of sulfur trioxide will be formed upon the complete reaction of 21.2 grams of oxygen gas with excess sulfur dioxide?

Question

sulfur dioxide (g) + oxygen (g) sulfur trioxide (g)

Answer 1

Here is an example stoichiometry problem I've posted. Just follow the steps.
http://www.jiskha.com/science/chemistry/stoichiometry.html

Answer 2

According to the following reaction, how many grams of water will be formed upon the complete reaction of 21.6 grams of oxygen gas with excess hydrogen sulfide?

2 H2S (g) + 3 O2 (g) = 2 H2O (l) + 2 SO2 (g)