85.1k views
1 vote
Magnesium burns in air with a dazzling brilliance to produce magnesium oxide:

2Mg(s)+O₂(g)→2MgO(s)
when 4.00 g of magnesium burns, the theoretical yield of magnesium oxide is ________ g.
A. 4.00
B. 0.165
C. 3.32
D. 13.3
E. 6.63

1 Answer

0 votes

Final answer:

e.6.63 g.

Using stoichiometry based on the molar masses of magnesium and magnesium oxide, the theoretical yield of MgO when 4.00 g of magnesium burns is found to be

Step-by-step explanation:

When 4.00 g of magnesium burns, the theoretical yield of magnesium oxide is calculated by using the stoichiometry of the reaction 2Mg(s) + O₂(g) → 2MgO(s). To find the theoretical yield, we first need to determine the molar mass of magnesium (Mg) and magnesium oxide (MgO), which are approximately 24.31 g/mol and 40.31 g/mol, respectively.

Next, we calculate the number of moles of magnesium in 4.00 g:


4.00 g Mg * (1 mol Mg / 24.31 g Mg) ≈ 0.1646 moles Mg

Since the reaction shows a 1:1 mole ratio between Mg and MgO, this means 0.1646 moles of magnesium will yield 0.1646 moles of MgO. Finally, we calculate the mass of the MgO produced:

0.1646 moles MgO * (40.31 g MgO / 1 mol MgO) ≈ 6.63g MgO

The correct answer is therefore E. 6.63g.

User Sanu
by
7.9k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.