If 62.0 grams of magnesium metal (mg) react with 55.5 grams of oxygen gas (o2) in a synthesis reaction, how many grams of the excess reactant will be left over when the reaction is complete?

be sure to write out the balanced equation for this reaction and to show all of your work.

14.1648 grams of oxygen gas will be left.

Explanation:

Moles of magnesium metal =

Moles of oxygen gas =

According to reaction, 2 mol of magnesium react with 1 mol of oxygen gas .

Then 2.5833 moles of magnesium will react with:

of oxygen gas.

Moles of oxygen left unreacted =1.7343 mol - 1.29165 mol = 0.44265 mol

Oxygen gas is an excessive reagent.

Mass of 0.44265 moles of oxygen gas:

0.44265 mol × 32 g/mol = 14.1648 g

14.1648 grams of oxygen gas will be left.

1 is the answer to this problem