Question

A mixture contains KClO₃ and KCl. When the mixture is heated, only the KClO₃ decomposes via the following reaction:

2KClO₃ (s) → 3O₂ (g) + 2KCl (s)

In an experiment to determine the percent KClO₃ in a KClO₃/KCl mixture, the mixture was heated in a crucible several times in order to bring it to constant mass. The following experimental data was obtained.

Before Heating

Mass empty crucible + lid = 21.84 g

Mass crucible + lid+ KClO₃/KCl mixture = 26.19 g

After Heating

Mass crucible + lid+ contents (after final heating ) = 24.52 g


Complete the following table

Decomposition of KClO3 in the Mixture
Mass crucible + lid + KClO3/KCl mixture (before heating)	(A)   g
Mass KClO3/KCl mixture	(B)   g
Mass crucible + lid + contents (after final heating)	(C)   g
Mass oxygen evolved (mass lost on heating)	(D)   g
Mass KClO3 in mixture (stoichiometric calculation from the mass of oxygen evolved)	(E)    g
%KClO3 in mixture (g KClO3/g mixture then multiply by 100)	(F)   %

Answer 1