# What is the stoichiometric equation for the formation of SO_3?

Well you gots $2 S \left(s\right) + 3 {O}_{2} \left(g\right) \rightarrow 2 S {O}_{3} \left(g\right)$
$S \left(s\right) + \frac{3}{2} {O}_{2} \left(g\right) \rightarrow S {O}_{3} \left(g\right)$...............