Question #6584b

Sep 15, 2017

${\text{4 moles KClO}}_{3}$

Explanation:

The key here is the balanced chemical equation that describes this decomposition reaction

$2 {\text{KClO"_ (3(s)) stackrel(color(white)(acolor(red)(Delta)aaa))(-> ) 2"KCl"_ ((s)) + 3"O}}_{2 \left(g\right)}$

Take a look at the coefficients added to the chemical species that take part in the reaction.

In this case, you know that for every $2$ moles of potassium chlorate that undergo decomposition, you get $2$ moles of potassium chloride and $3$ moles of oxygen gas.

• $2 {\text{KClO"_3 -> "2 moles of KClO}}_{3}$
• $\text{2KCl " -> " 2 moles KCl}$
• $3 {\text{O"_2 -> "3 moles O}}_{2}$

This means that in order for the reaction to produce $6$ moles of oxygen gas, you need to have

$6 \textcolor{red}{\cancel{\textcolor{b l a c k}{{\text{moles O"_2))) * overbrace( "2 moles KClO"_3/(3color(red)(cancel(color(black)("moles O"_2)))))^(color(blue)("given by the balanced chemical equation")) = color(darkgreen)(ul(color(black)("4 moles KClO}}_{3}}}}$