Oxidation Number
The oxidation number of Cr in K₂Cr₂O₇ is:
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About This Question
- Subject
- chemistry
- Chapter
- redox reactions and electrochemistry
- Topic
- oxidation number
- Difficulty
- Easy
- Year
- 2025
Solution
Correct Answer:
+6
To find the oxidation number of Chromium (Cr) in Potassium Dichromate (K2Cr2O7):
- Standard Values: K=+1 (Group 1), O=−2 (typical).
- Let the oxidation number of Cr be 'x'.
- Total charge on the neutral molecule = 0.
- Calculation: 2(+1)+2(x)+7(−2)=0 2+2x−14=0 2x=12⇒x=+6
- Thus, each chromium atom in dichromate is in the +6 oxidation state.
This easy difficulty chemistry question is from the chapter redox reactions and electrochemistry, covering the topic of oxidation number. It appeared in the 2025 exam.
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