Question

How many grams of Mg are needed to produce 224 g of MgO in the complete reaction of Mg

with oxygen gas?

Answer 1

134.4 g of Mg

Step-by-step explanation:

reaction:

2Mg + O2 ➡️ 2MgO

1) find the mol of MgO

mol = mass / molar mass

mass = 224 g

molar mass = 24+16 = 40

mol = 224 / 40

= 5.6 moles

2 mol = 5.6 moles

2) find the mass of Mg

mass = mol × molar mass

mol = 5.6

molar mass = 24

mass = 5.6 × 24

= 134.4 g