Question

You heat 3.939 g of a mixture of Fe3O4 and FeO to form 4.197 g Fe2O3. The mass of oxygen reacted is

Answer 1

To find the mass of oxygen reacted, we need to calculate the mass of oxygen present in the reactants and subtract it from the mass of oxygen in the product.

Step-by-step explanation:

To find the mass of oxygen reacted, we need to calculate the mass of oxygen present in the reactants and subtract it from the mass of oxygen in the product. First, we calculate the amount of oxygen in Fe₃O₄ and FeO:

• Mass of Fe₃O₄ = 3.939 g
• Molar mass of Fe₃O₄= 231.54 g/mol (from atomic masses)
• Moles ofFe₃O₄ = mass / molar mass
• = 3.939 g / 231.54 g/mol
• = 0.017 mol
• Moles of oxygen in Fe₃O₄= 0.017 mol x 4 (from the balanced equation) = 0.068 mol
• Mass of FeO = total mass - mass of Fe₃O₄
• = 4.197 g - 3.939 g
• = 0.258 g
• Molar mass of FeO = 71.85 g/mol (from atomic masses)
• Moles of FeO = mass / molar mass
• = 0.258 g / 71.85 g/mol
• = 0.0036 mol
• Moles of oxygen in FeO = 0.0036 mol x 1 (from the balanced equation) = 0.0036 mol

Therefore, the total moles of oxygen in the reactants is 0.068 mol + 0.0036 mol = 0.0716 mol.

The molar mass of oxygen is 16.00 g/mol. Multiplying the number of moles by the molar mass gives the mass of oxygen.

Mass of oxygen reacted = 0.0716 mol x 16.00 g/mol

= 1.144 g.

Answer 2

Step-by-step explanation:

A mixture of differet iron oxides is heated and they it absorbs oxygen from the air to form iron (II) oxide. The reaction can be represented like this:

2 Fe₃O₄ + 2 FeO + O₂ ----> 4 Fe₂O₃

The mass of the mixture of Iron oxides is 3.939 g. The mass of Fe₂O₃ formed is greater than the original mass, it is 4.197 g. That means that the sample absorbed oxygen.

mass of Fe₃O₄ + mass of FeO = 3.939 g

mass of Fe₂O₃ = 4.197 g

The law of conservation of mass states that no mass is loss or created in a chemical reaction. A mass balance can be written:

mass of Fe₃O₄ + mass of FeO + mass of O₂ = mass of Fe₂O₃

The known values can be replaced in the equation, and it can be solved for mass of O₂ to obtain the answer to the problem.

mass of Fe₃O₄ + mass of FeO + mass of O₂ = mass of Fe₂O₃

mass of O₂ = mass of Fe₂O₃ - (mass of Fe₃O₄ + mass of FeO)

mass of O₂ = 4.197 g - 3.939 g

mass of O₂ = 0.258 g

Answer: the mass of oxygen reacted is 0.258 g