Question

How many grams of magnesium are needed to completely react

Answer 1

97.22 grams of magnesium is needed.

Explanation:

The molar ratio of Mg to O2  to make MgO is 2:1

Here, we have 2 moles of O2, therefore we need 4 moles of Mg.

1 mol of Mg = 24.305 g

Therefore

4 moles of Mg = 4 $\times$ 24.305 g

                        = 97.22 g

Hence we need 97.22grams of magnesium are needed to completely reactwith 2.00 mol of O2 in the synthesis reaction that producesmagnesium oxide.