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Iron content in haematite (Fe₂O₃): select the closest percentage by mass Haematite iron ore composition question for basic metallurgy and materials engineering. Choose the nearest iron percentage.

Difficulty: Easy

Correct Answer: 70%

Explanation:

Given

Haematite is Fe₂O₃.

Step-by-Step calculation
M(Fe₂O₃) ≈ 2 × 55.85 + 3 × 16.00 = 111.70 + 48.00 = 159.70 g/molMass of Fe in Fe₂O₃ = 111.70 g%Fe = (111.70 / 159.70) × 100 ≈ 69.9% ≈ 70%

Concept
Ideal haematite contains about 70% iron by mass; the rest is oxygen (ignoring gangue).

Final Answer
70%

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