Question

$...S{O}_2\left(g\right)+....O_2\left(g\right)\to ...S{O}_3\left(g\right)$

According to the above unbalanced equation, how many moles of $S{O}_2\left(g\right)$ will react completely with 1 mole of $O_2\left(g\right)$ ?

• A. $0.5$ mol
• B. $1$ mol
• C. $2$ mol
• D. $3$ mol
• E. $4$ mol

Answer 1

The correct option is C $2$ mol

The unbalanced chemical equation is $S{O}_2\left(g\right)+O_2\left(g\right)\to S{O}_3\left(g\right)$
In this equation, S atoms are already balanced. Balance O atoms.

$S{O}_2\left(g\right)+\frac{1}{2}{O}_2\left(g\right)\to S{O}_3\left(g\right)$

This is the balanced chemical equation.
1 mole of $S{O}_2\left(g\right)$ completely reacts with $\frac{1}{2}$ moles of $O2\left(g\right)$.
Hence, 2 moles of $S{O}_2\left(g\right)$ will completely react with 1 mole of $O_2\left(g\right)$.

Hence, the correct option is $\text{C}$