Solve this multiple-choice question and choose the correct option.

Given data & assumption Common iron ores: hematite = Fe2O3, magnetite = Fe3O4, siderite = FeCO3, limonite/goethite ≈ hydrated Fe(III) oxides. Concept/ApproachMagnetite’s correct formula is Fe3O4. In the options, Fe₃OH₄ appears to be a typographical variant and is understood here as Fe3O4. The others correspond to hematite (Fe₂O₃), siderite (FeCO₃), and hydrated oxides. Final AnswerFe₃OH₄ (intended as Fe3O4)

Home » IIT JEE » Chemistry

Ore identification (iron): Magnetite is an important iron ore—select its correct chemical formula from the options provided. Match the common name ‘‘magnetite’’ with its standard oxide formula. Choose the correct option.

Difficulty: Easy

Fe₂O₃
Fe₃OH₄
FeCO₃
3Fe₂O₃ · 3H₂O

Correct Answer: Fe₃OH₄

Explanation:

Given data & assumption

Common iron ores: hematite = Fe₂O₃, magnetite = Fe₃O₄, siderite = FeCO₃, limonite/goethite ≈ hydrated Fe(III) oxides.

Concept/ApproachMagnetite’s correct formula is Fe₃O₄. In the options, Fe₃OH₄ appears to be a typographical variant and is understood here as Fe₃O₄. The others correspond to hematite (Fe₂O₃), siderite (FeCO₃), and hydrated oxides.

Final AnswerFe₃OH₄ (intended as Fe₃O₄)

← Previous Question Next Question→

More Questions from Chemistry

Acid–base species: Identify the hydronium ion among the following chemical species. Recall that hydronium is protonated water (the actual carrier of ‘‘H⁺’’ in aqueous solution). Choose the correct option.
Atomic numbers vs mass numbers: The mass number (A) of an atom equals what count of subatomic particles? Relate A to the composition of the nucleus (protons and neutrons). Choose the correct option.
Indian mineral resources: Which ore is found in abundance in India compared to the other options listed? Consider well-known placer deposits and strategic reserves in India. Choose the correct option.
Applied X-ray detection: Which of the following items is particularly amenable to detection by soft X-rays (lower energy, higher absorption by light elements)? Consider penetration and contrast for organic materials. Choose the correct option.
Polymers (processing behavior): A material that sets into a permanently infusible shape when heated and pressed is called what? Differentiate between thermoplastic (reversible softening) and crosslinked systems. Choose the correct option.
Fuels (antiknock rating): The octane number scale assigns a value of zero to which reference fuel? Recall the two primary standards used to define octane numbers. Choose the correct option.
Water treatment (permanent hardness): Which method cannot remove permanent hardness due to Ca/Mg chlorides/sulfates? Identify the technique ineffective against non-bicarbonate hardness. Choose the correct option.
Allotropy of phosphorus: What is the molecular formula of elemental (white) phosphorus as commonly encountered? Recall the tetra-atomic molecular form of white phosphorus. Choose the correct option.
Bohr–hydrogen energy levels: If the ionization energy of hydrogen from the ground state equals x kJ mol⁻¹, what energy is required to excite an electron from n = 2 to n = 3? Use Eₙ ∝ −1/n² and compute ΔE between levels. Choose the correct option.
Ore of aluminium (metallurgy): Identify the most important commercial ore of aluminium used for metal extraction. Select the widely occurring hydrated oxide ore. Choose the correct option.

Discussion & Comments

No comments yet. Be the first to comment!

Join Discussion