If 48 g of magnesium reacts with oxygen gas, how many grams of magnesium oxide will be formed according to the following equation? 2 mg + o2 —-> 2 mgo

If 48 g of magnesium react with gaseous oxygen, 80 grams of magnesium oxide will form.

Explanation:

First of all you must know the amount of mass that reacts and is produced from each compound stochemically (that is, the relationship between the amount of reagents and products in a chemical reaction).

For that you must know the atomic mass of each element, read in the periodic table:

Then,  the compounds involved in the reaction have a molar mass, that is, the mass in one mole of the compound, of:

But in the reaction 2 Mg + O₂ —-> 2 MgO it is observed that 2 moles of Mg and 1 mole of O₂ react, and 2 moles of MgO are formed. Then stoichiometrically they react and the following mass quantities are produced:

By stoichiometry you can see that when reacting 48 g of Mg, 80 g of MgO are formed.  Expressed in another way, if 48 g of magnesium react with gaseous oxygen, 80 grams of magnesium oxide will form.

the answer your looking for is c).