Question

The decomposition of potassium chlorate, KClO3, gives oxygen gas and solid potassium chloride. How many grams of KClO3 are needed to produce 5.00 L of Oxygen gas at STP?

Suppose that the reaction described above produces 4.80 L of O2 in the laboratory. What is the percent yield?

Answer 1

Here is a worked example using KClO3.
Remember mols x 22.4 L/mol = L.
http://www.jiskha.com/science/chemistry/stoichiometry.html