An original samplemof an unknown potassium chloride/potassium cholate mixture weighed 1.042g before heating and 0.943g after heating. How many grams of oxygen were released?

Answer 1

2KClO3 ==> 2KCl + 3O2
Loss in mass = mass O2 lost = 1.042-0.943 = 0.099
mols O2 = grams/molar mass
Using the coefficients in the balanced equation, convert mols O2 to mols KClO3.
Then convert mols KClO3 to grams KClO3 with g = mols x molar mass.