# Question #57781

Apr 26, 2017

3 moles of ${O}_{2}$ are needed; 6 moles of MgO are produced.

#### Explanation:

The balanced equation is

$2 M g + {O}_{2} \rightarrow 2 M g O$

We see that the ratio of Mg to ${O}_{2}$ is 2:1

This means you need twice as many moles of magnesium as oxygen, or if you prefer, half as much oxygen as magnesium.

Either way, the 6 moles of Mg require 3 moles of ${O}_{2}$ to react completely.

We will get 6 moles of $M g O$, as the ratio between Mg and MgO is 2:2 (or 1:1).