Question

what is the missing coefficient to make a balanced equation? 2kclo₃ → 2kcl + ?o₂

Explanation:

Step1: Count oxygen atoms on left - hand side

On the left - hand side, in $2KClO_3$, the number of oxygen atoms is $2\times3 = 6$.

Step2: Determine coefficient for $O_2$ on right - hand side

Let the coefficient of $O_2$ be $x$. Each $O_2$ molecule has 2 oxygen atoms. So the number of oxygen atoms on the right - hand side is $2x$. We set $2x=6$, then $x = 3$.

Answer:

3