Correct Option
The correct option is (c).
Explanation
Magnetic separation is a physical technique used to separate components of a mixture based on their differing magnetic susceptibilities. This method relies on the fact that some materials are strongly attracted to magnetic fields (ferromagnetic), while others are not.
Statement-wise Analysis:
- Statement 1 is Incorrect. Soil is not completely free of magnetic particles. Naturally occurring soils often contain magnetic minerals such as magnetite (Fe3O4) and maghemite (γ-Fe2O3). The concentration of these magnetic minerals varies across different geographical regions, but it is factually incorrect to state that soil is universally free of magnetic particles.
- Statement 2 is Correct. Iron is a ferromagnetic material, meaning it is strongly attracted to a magnet. Most soil components (silica, clay, organic matter) are non-magnetic. Therefore, passing a magnet over a mixture of soil and iron filings will attract the iron filings, effectively separating them from the soil.
- Statement 3 is Correct. The fundamental principle behind this separation is the difference in magnetic properties between the components. The process works because one component (iron) is magnetic and the other (soil) is largely non-magnetic.
Key Takeaway:
Mixtures containing ferromagnetic substances (like iron) and non-magnetic substances can be separated using magnetic separation, which exploits the difference in their response to a magnetic field.