Pink colour of acidified `KMnO_(4)` is decolourised but there is no evolution of any gas.This may happen with the compound containing the following acid radical.

Options

A. `SO_(3)^(2-)`
B. `NO_(2)^(-)`
C. `S^(2-)`
D. All of these

Answer

D

Explanation

`(1) 5SO_(3)^(2-) +2MnO_(4)^(-)+ 6H^(+) to 2Mn^(2+) +5SO_(4)^(2-)+3H_(2)O`
`(2) 2MnO_(4)^(-)+5NO_(2)^(-)+6H^(+) to 2Mn^(2+)+5NO_(3)^(-) +3H_(2)O`
`(3) 2MnO_(4)^(-) +H_(2)S +6H^(+) to 2Mn^(2+) +5S darr +8H_(2)O`