KCET2010ChemistryGeneral Principles and Processes of Isolation of Metals
In chromite ore, the oxidation number of iron, and chromium are respectively
Options
- A+3,+2
- B+3,+6
- C+2,+6
- D+2,+3
Correct answer
D. +2,+3
Step-by-step solution
Chromite or chrome iron ore is FeCr ₂ O ₄ . Its actual composition is FeO Cr ₂ O ₃ . In FeO , oxidation state of Fe is calculated as aligned x +(-2) &=0 x &=+2 aligned Similarly, in Cr ₂ O ₃ , the oxidation state of Cr is calculated as aligned 2 x+(-2) 3 &=0 2 x &=+6 x &=+3 aligned