Question

If this reaction produced 23.9 g KCl, how many grams of O2 were produced?

Answer 1

The reaction must be the decomposition of KClO3 to the formation of KCl and O2

2KClO3 ========== 2KCl + 3O2

Molar mass of KCl = 74.5 gm/mol

Number of moles of KCl = Mass/Molar mass = 23.9/74.5 = 0.321 moles

Moles of O2 formed = 3/2 * moles of KCl (As per balanced reaction coefficients)

=> 3/2 * 0.321

=> 0.4815 moles

Molar mass of O2 gas = 31.98 gm/mol

Mass of O2 produced = number of moles * molar mass = 0.4815 mol * 31.98 gm/mol = 15.4 grams of O2 gas