In the reaction #2Mg + O_2 -> 2MgO#, the law of definite proportions states that for every 2 moles of #Mg# you will need how many moles of #O_2#?
Feb 28, 2016
It's in the balanced equation. Each number before a compound corresponds to how many miles you use, and when there is no number you put in a 1. So 2