Ques. 1JEE Main 2024, 30 January (Evening Shift)
Total number of species from the following which can undergo disproportionation reaction is . H2O2, ClO3-, P4, Cl2, Ag, Cu+1, F2, NO2, K+
Answer
6
Solution
Disproportionation: the same element is oxidised and reduced ⇒ it must be in an intermediate oxidation state
H2O2 (O: −1) → H2O (−2) + O2 (0) ✓
ClO3- (Cl: +5) → Cl- (−1) + ClO4- (+7) ✓
P4 (0) → PH3 (−3) + H2PO2- (+1) ✓
Cl2 (0) → Cl- (−1) + ClO- (+1) ✓
Cu+ (+1) → Cu (0) + Cu2+ (+2) ✓
NO2 (N: +4) → NO2- (+3) + NO3- (+5) ✓
Ag (0, lowest state), K+ (+1, highest state), F2 (F has no positive state) ⇒ cannot disproportionate
∴ 6 species
Answer: 6