Question

1g of KCLO3 was heated under such condition that a part of it decomposed accordingly to the eqution 2KCLO3 gives 2KCL+3O2 and remaining decomposed as 4KCLO3 gives 3KCLO4+KCL. If the O2 evolved was 146.8ml at STP calculate the % by weight of KCLO4 in the residue.

Answer 1

Answer:

245g2KClO3→149g2KCl+96g3O2

490g4KClO3→415.5g3KClO4+74.5KCl

Given, total weight of the sample =1 g

Let x g of KClO3 be converted to KCl and O2 and (1−x) g be converted to KClO4 and KCl.

Given, 146.8 mL of O2 was evolved at STP.

Weight of O2=22400146.8×32=0.2097 g

 Weight of KClO3  converted to KCl and O2= x=96245×0.2097=0.5352 g

Weight of KClO4 formed from remaining KClO