You are given 1.226 g of a mixture of KClO3 and KCl. When heated, the KClO3 decomposes to KCl and O2,

Question

2 KClO3 (s) → 2 KCl (s) + 3 O2 (g),
and 246 mL of O2 is collected over water at 24 °C. The total pressure of the gases in the collection flask is 755 torr. What is the weight percentage of KClO3 in the sample?
The formula weight of KClO3 is 122.55 g/mol. The vapor pressure of water at 24 °C is 22.4 torr.

Answer 1

2 KClO3 (s) → 2 KCl (s) + 3 O2 (g)

Use PV = nRT and solve for mols O2 at the conditions listed.
Using the coefficients in the balanced equation, convert mols O2 to mols KClO3.
Convert mols KClO3 to grams by g = mols x molar mass
Then %KClO3 = (mass KClO3/mass sample)*100 = ?