# Consider the following balance equation: 2Fe_2O_3 + 3S \to 3SO_2 + 4Fe. How many moles of sulfur...

## Question:

Consider the following balance equation: {eq}2Fe_2O_3 + 3S \to 3SO_2 + 4Fe {/eq}. How many moles of sulfur dioxide are made if 12 moles of iron III oxide are used?

## Mole Ratios

A balanced chemical equation provides mole ratios that can be used in stoichiometry problems. The mole ratios come from the coefficients in front of each particle in the equation. For example, in the balanced chemical equation {eq}2Fe_2O_3 + 3S \to 3SO_2 + 4Fe {/eq}, the mole ratio of sulfur to iron is 3 moles or sulfur to 4 moles of iron, of 3:4. Ratios can always be reversed if it is more convenient. For example, you could write this mole ratio as 4 moles of iron to 3 moles of sulfur, or 4:3.