Question

When 0.0976 g of magnesium was heated in air, 0.1627 g of magnesium oxide $\left(MgO\right)$ was produced. What is the mass of oxygen needed to produce 0.1627 g of $MgO$?

• A. 0.0651 g
• B. 0.0561 g
• C. 0.0115 g
• D. 0.6051 g

Answer 1

The correct option is A 0.0651 g

Total mass of reactants = Total mass of products
Mass of $Mg$ + Mass of $O$ = Mass of $MgO$
$0.0976\text{g}$ + mass of $O=0.1627\text{g}$
Mass of $O=0.1627-0.0976=0.0651\text{g}$