24.5 g of KClO3 is decomposed: 2KClO3 -> 2KCl + 3O2. If the yield is 85%, find the mass of O2 obtained in grams, to two decimals (K = 39, Cl = 35.5, O = 16).

JEE Main levelNumerical answerDifficulty 2 of 3mc192

$24.5 g$ of $KClO X_{3}$ is decomposed: $2 KClO X_{3} 2 KCl + 3 O X_{2}$ . If the yield is $85%$ , find the mass of $O X_{2}$ obtained in grams, to two decimals (K = 39, Cl = 35.5, O = 16).

Numerical answer type, answer in g, tolerance 0.01.

n(KClO3) = 24.5/122.5 = 0.20 mol gives 0.300 mol O2 = 9.60 g theoretically. At 85% yield the mass is 9.60 x 0.85 = 8.16 g.