Question

Oxygen can be produced in the laboratory by the reaction
2 KClO3(s) → 2 KCl(s) + 3 O2(g) .
How much potassium chlorate is needed to produce 2.75 L of oxygen, collected over water at 37◦C and 94.9 kPa? The vapor pressure of water at 37◦C is 6.28 kPa.
1. 0.189 mol
2. 0.142 mol
3. 6.30 × 10−2 mol 4. 7.20 × 10−2 mol 5. 9.45 × 10−2 mol

Answer 1

Here is an example problem using KClO3 to product oxygen. Just follow the steps in reverse to find mols KClO3. Use PV = nRT to find mols O2 needed.
http://www.jiskha.com/science/chemistry/stoichiometry.html

Answer 2

0.189