Match the oxidation state of the atom named in List-I with List-II.
| List-I | List-II |
| (A) Mn in MnO4− | (p) +1 |
| (B) Cr in CrO42− | (q) +2 |
| (C) Zn in ZnO22− | (r) +7 |
| (D) Ag in [Ag(CN)2]− | (s) +6 |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → A-r, B-s, C-q, D-p
The oxidation state x of the named atom comes from charge balance: the oxidation numbers of all atoms add up to the charge on the species (O = −2, \( \ce{CN^-} \) = −1).
(A) Mn in MnO4− — This matches (r) +7. x + 4(−2) = −1, so x = +7.
(B) Cr in CrO42− — This matches (s) +6. x + 4(−2) = −2, so x = +6.
(C) Zn in ZnO22− — This matches (q) +2. x + 2(−2) = −2, so x = +2.
(D) Ag in [Ag(CN)2]− — This matches (p) +1. x + 2(−1) = −1, so x = +1.