alleryPotassium dichromate (K₂Cr₂O₇) is prepared from which ore?
APyrolusite (MnO₂)
BChromite (FeCr₂O₄)
CBauxite (Al₂O₃·2H₂O)
DHematite (Fe₂O₃)
Answer & Solution
Correct answer: B. Chromite (FeCr₂O₄)
**Chromite ore (FeCr₂O₄)**
→ fused with Na₂CO₃ in presence of O₂
→ Na₂CrO₄ (yellow) → acidified with H₂SO₄
→ Na₂Cr₂O₇ (orange) → treated with KCl → **K₂Cr₂O₇**.
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