4. problem 4: formation of sulfur dioxide\n● balanced equation: 2so₂ + o₂ → 2so₃\n● given: 4 moles of so₂…

Explanation:

Step1: Calculate moles of $O_2$ needed for $SO_2$ reaction

From the balanced equation $2SO_2 + O_2\rightarrow 2SO_3$, the mole - ratio of $SO_2$ to $O_2$ is 2:1. Given 4 moles of $SO_2$, the moles of $O_2$ required for complete reaction of $SO_2$ is $n_{O_2}=\frac{4\ mol\ SO_2}{2}= 2\ mol\ O_2$.

Step2: Compare required and given moles of $O_2$

We are given 3 moles of $O_2$, and we only need 2 moles of $O_2$ to react with 4 moles of $SO_2$. Since the moles of $SO_2$ will be completely consumed first (as we have excess $O_2$), $SO_2$ is the limiting reactant.

Answer:

$SO_2$ is the limiting reactant.