Question

if 6 mole of KClO3 decomposed according to the following reaction :

• KClO3 ---> KCl + 3/2 O2
• ​KClO3 ---> KClO4 + KCl

​calculate the moles of KClO4 produced if moles of O2 produced are 3

Answer 1

Dear Student,

$$\begin{gathered} {\mathrm{KClO}}_3\to \mathrm{KCl}+\frac{3}{2}{\mathrm{O}}_2..\left(\mathrm{i}\right) \\ 1\mathrm{mol}\raisebox{1ex}{$3$}\!\left/ \!\raisebox{-1ex}{$2$}\right.\mathrm{mol} \\ 4{\mathrm{KClO}}_3\to 3{\mathrm{KClO}}_4+\mathrm{KCl}..\left(\mathrm{ii}\right) \\ 4\mathrm{mol}3\mathrm{mol} \\ 1\mathrm{mol}\mathrm{of}{\mathrm{KClO}}_3\mathrm{produce}\raisebox{1ex}{$3$}\!\left/ \!\raisebox{-1ex}{$2$}\right.\mathrm{mol}\mathrm{of}{\mathrm{O}}_2 \\ \mathrm{So},3\mathrm{mol}\mathrm{of}{\mathrm{O}}_2\mathrm{will}\mathrm{be}\mathrm{produced}\mathrm{by}\frac{1}{\left({\displaystyle \raisebox{1ex}{$3$}\!\left/ \!\raisebox{-1ex}{$2$}\right.}\right)}\times 3=2\mathrm{mol}\mathrm{of}{\mathrm{KClO}}_3 \\ \mathrm{So},\mathrm{left}\mathrm{over}\mathrm{moles}\mathrm{of}{\mathrm{KClO}}_3=6-2=4\mathrm{mol} \\ \mathrm{From}\mathrm{the}\mathrm{second}\mathrm{reaction}, \\ 4\mathrm{mol}\mathrm{of}{\mathrm{KClO}}_3\mathrm{reacts}\mathrm{to}\mathrm{give}3\mathrm{mol}\mathrm{of}{\mathrm{KClO}}_4 \\ \mathrm{Hence},3\mathrm{mol}\mathrm{of}{\mathrm{KClO}}_4\mathrm{are}\mathrm{produced}. \end{gathered}$$