Question

. Calculate the mass of O2 produced if 3.450 g potassium chlorate is completely decomposed by heating in presence of a catalyst ( Manganese dioxide).

Answer 1

2 KClO3(s) → 3 O2(g) + 2 KCl(s)

Note: MnO2 (Manganese Dioxide) is not part of the reaction. A catalyst lowers the activation energy and increases both forward and reverse reactions at equal rates.

molar mass of KClO3 = 122.5
Moles of KClO3 = 3.45 / 122.55 = 0.028

Moles of O2 produce =
`(3)/(2) * 0.028`

= 0.042 moles

molar mass of O2 = 32

so, mass of O2 = 32 x 0.042 = 1.35 g