Respostas

2014-08-23T13:42:24-03:00
2Mg + O2 ⇒ 2MgO

1 mol de O2 ----------- 2 mols de MgO
32g -------------------- 2. (40 g)
32 --------------------- 80 g
x ----------------------- 40 g
80x = 1280
    x = 1280/80
    x = 16 g de O2