Question

2 KCIO3(s) -→2KCI(s) + 3 O2(g)

O2 gas is slightly soluble in water. How does this affect the reported
moles of KClO3 decomposed in the mixture? Explain.

Answer 1

If some O2 dissolves in water then the volume of the gas measured will be smaller. That means mols O2 gas measured will be smaller which means moles KClO3 decomposed will be smaller.