Among the following select the disproportionation reaction ?
(i) `2Pb(NO_(3))_(2) rarr 2PbO+4NO_(2)+O_(2)`
(ii) `I_(2) rarr I^(-)+IO_(3)^(-)`
(iii) `3Cl_(2)+6NaOH rarr 5NaCl+NaClO_(3)+3H_(2)O`
(iv) `P_(4)+3NaOH+3H_(2)O rarr 3NaH_(2)PO_(2)+PH_(3)`

Options

A. `(i), (ii), (iii)`
B. `(ii), (iii), (iv)`
C. `(i), (iii), (iv)`
D. All of these

Answer

B

Explanation

A reaction in which the same species is simultaneously oxidised as well as reduced is called a disproportionation reaction.
(`ii`) `overset(0)(I_(2)) rarr overset(-1)(I^(-))+overset(+5)(IO_(3)^(-))`
(`iii`) `overset(0)(3Cl_(2))+6NaOH rarr 5 overset(-1)(NaCl)+overset(+5)(NaClO_(3))+3H_(2)O`
(`iv`) `overset(0)(P_(4))+3NaOH+3H_(2)O rarr 3NaH_(2)overset(+1)(P)O_(4)+overset(-3)(P)H_(3)`