Match List I with List II for the oxidation state of central atoms:
|
List-I |
List-II |
|
(A) $Cr_2O_7^{2-}$ |
(I) +3 |
|
(B) $MnO_4^-$ |
(II) +5 |
|
(C) $VO_3^-$ |
(III) +7 |
|
(D) $FeF_6^{3-}$ |
(IV) +6 |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → (A)-(IV), (B)-(III), (C)-(II), (D)-(I)
Here is a detailed explanation of how the oxidation states for each compound were determined, and how the correct matching is obtained:
(A) Cr₂O₇²⁻ (Dichromate ion):
The formula for the dichromate ion is Cr₂O₇²⁻.
Oxygen generally has an oxidation state of -2.
Let the oxidation state of chromium (Cr) be \( x \).
The total charge of the ion is -2.
The sum of the oxidation states must equal the total charge:
\(2x + 7(-2) = -2\)
\(2x - 14 = -2 ⇒ 2x = 12 ⇒ x = +6\)
So, the oxidation state of chromium (Cr) in Cr₂O₇²⁻ is +6.
(B) MnO₄⁻ (Permanganate ion):
The formula for the permanganate ion is MnO₄⁻.
Oxygen has an oxidation state of -2.
Let the oxidation state of manganese (Mn) be \( x \).
The total charge on the ion is -1.
The sum of the oxidation states must equal the charge on the ion:
\(x + 4(-2) = -1\)
\(x - 8 = -1 ⇒ x = +7\)
So, the oxidation state of manganese (Mn) in MnO₄⁻ is +7.
(C) VO₄³⁻ (Vanadate ion):
The formula for the vanadate ion is VO₄³⁻.
Oxygen has an oxidation state of -2.
Let the oxidation state of vanadium (V) be \( x \).
The total charge on the ion is -3.
The sum of the oxidation states must equal the charge on the ion:
\(x + 4(-2) = -3\)
\(x - 8 = -3 ⇒ x = +5\)
So, the oxidation state of vanadium (V) in VO₄³⁻ is +5.
(D) FeF₆³⁻ (Hexafluoroferrate ion):
The formula for the hexafluoroferrate ion is FeF₆³⁻.
Fluorine has an oxidation state of -1.
Let the oxidation state of iron (Fe) be \( x \).
The total charge on the ion is -3.
The sum of the oxidation states must equal the charge on the ion:
\(x + 6(-1) = -3\)
\(x - 6 = -3 ⇒ x = +3\)
So, the oxidation state of iron (Fe) in FeF₆³⁻ is +3.
The correct answer is Option (2) → (A)-(IV), (B)-(III), (C)-(II), (D)-(I)