Question

Question #57781

Answer 1

3 moles of `O_2` are needed; 6 moles of MgO are produced.

Explanation:

The balanced equation is

`2Mg+O_2 rarr 2MgO`

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 `MgO`, as the ratio between Mg and MgO is 2:2 (or 1:1).