What is the molecular formula of the compound consisting of iron and oxygen in the ratio of 3:4?

• How many oxygen atoms are present in the compound Fe₃O₄?
• What is the total mass of iron in 28 grams of Fe₃O₄?

How do you calculate the number of moles of Fe in 132 grams of Fe₃O₄?

The compound made of iron and oxygen in a 3:4 ratio is known as iron(IV) oxide, with the molecular formula Fe₃O₄.

Oxygen Atoms in Fe₃O₄

In the formula Fe₃O₄, there are 4 oxygen atoms present.

Total Mass of Iron in 28 Grams of Fe₃O₄

To find the total mass of iron in 28 grams of Fe₃O₄, first calculate the molar mass:

• Molar mass of Fe = 55.85 g/mol
• Molar mass of O = 16.00 g/mol
• Molar mass of Fe₃O₄ = (3 × 55.85) + (4 × 16.00) = 159.7 g/mol

Next, find the mass of iron in the compound:

• Mass of iron in Fe₃O₄ = (3 × 55.85) = 167.55 g
• Proportion of iron = 167.55 g / 159.7 g/mol ≈ 0.95
• Mass of iron in 28 g of Fe₃O₄ = 28 g × 0.95 ≈ 25.6 g

Calculating Moles of Iron in 132 Grams of Fe₃O₄

To determine the number of moles of iron in 132 grams of Fe₃O₄, follow these steps:

• First, calculate the moles of Fe₃O₄: 132 g / 159.7 g/mol ≈ 0.826 moles.
• Since each mole of Fe₃O₄ contains 3 moles of Fe, multiply: 0.826 moles × 3 ≈ 2.48 moles of Fe.

Thus, there are approximately 2.48 moles of iron in 132 grams of Fe₃O₄.