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. $0.0651\text{g}$
• B. $0.0782\text{g}$
• C. $0.0440\text{g}$
• D. $0.0200\text{g}$

Answer 1

The correct option is A $0.0651\text{g}$

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