Question

Given below is a chemical reaction. 4Fe + 3O2 -> 2Fe2O3 How much Fe2O3is formed when 5.6 g of Iron reacts completely with oxygen?

• A. 8g
• B. 80g
• C. 160g
• D. 16g

Answer 1

Answer:

A. 8g

• First, we need the molar masses of the substances involved

  Molar mass of Fe=56

• Molar mass of oxygen=16

• Molar mass of Fe₂O₃=160

• moles of Iron= given mass/molar mass=5.6/56=0.1mol

• The balanced equation is: 4Fe + 3O2 ---------->2Fe₂O₃

• The moles of Fe2O3 =moles of Fex2/4

• This means 2 moles of $Fe$ produce 1 mole of Fe2O3

• Since we have $0.1\text{ mol}$ of $Fe$:

  moles of Fe ₂O₃=.1/2=0.05 mol

• mass of 2Fe₂O₃₌ moles x molaer mass = .05mol x 160 g/mol = 8.0g