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Q15
(CISF/2026)
Science & Technology › Basic Science (Physics, Chemistry, Biology)
The oxidation state of Chromium is the same in all of the following compounds except one. CrO3, Cr2O3, CrCl3, Cr2(CO3)3 Select the compound whose oxidation state is different from others?
Result
Your answer:
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Correct:
A
Explanation
The oxidation state of an element represents the degree of oxidation of an atom in a chemical compound. By applying the rules of oxidation states (where Oxygen is typically -2 and Chlorine is -1), we can calculate the state for Chromium (Cr) in each compound:
- CrO3: x + 3(-2) = 0 ⇒ x = +6.
- Cr2O3: 2x + 3(-2) = 0 ⇒ 2x = 6 ⇒ x = +3.
- CrCl3: x + 3(-1) = 0 ⇒ x = +3.
- Cr2(CO3)3: Since the carbonate ion (CO3) has a charge of -2, 2x + 3(-2) = 0 ⇒ 2x = 6 ⇒ x = +3.
In CrO3 (Chromium trioxide), Chromium is in the +6 oxidation state, whereas in all other listed compounds, it is in the +3 oxidation state. Therefore, CrO3 is the correct answer.
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