# How many moles are necessary to react completely with four moles of propane in the reaction C_3H_8 + 5O_2 -> 3CO_2 + 4H_2O?

Feb 25, 2016

$20 m o l \text{ of } {O}_{2}$

#### Explanation:

I assume that the question is about how many moles of oxygen that will react completely with four moles of propane.

From the balanced equation:

${C}_{3} {H}_{8} + 5 {O}_{2} \to 3 C {O}_{2} + 4 {H}_{2} O$

Every 1 mole of ${C}_{3} {H}_{8}$ reacts with 5 moles of ${O}_{2}$ , therefore,

?molO_2=4cancel(molC_3H_8)xx(5molO_2)/(1cancel(molC_3H_8))=20 molO_2