Question

How much potassium chlorate should be heated to produce 2.24L of

oxygen at STP?

Answer 1

The balanced chemical equation for the reaction is:

2 KClO3(s) → 3 O2(g) + 2 KCl(s)


Molar mass of KClO3 = 39+35.5+16x3 = 122.5



Molar gas volume at STP = 22.4 litres

From the equation, 2 moles of KClO3 produce 3 moles of O2


⇒ 2 moles of KClO3 produce 3x22.4 litres of O2


22.4 L of O2 will be produced from = (22.4 x 2)/3x22.4

                                                        = 2/3  moles of KClO3



Mass of KClO3 = 2/3 x 122.5


                         = 81.67g

Answer 2

Answer: 8.16g of kclo3

Explanation: