Give four examples to show that acidified `KMnO_(4)` is an oxidising agent.

Explanation

(i) Acidified `KMnO_(4)` oxidises Iodide ion to Iodine
`(MnO_(4)^(-)+8H^(+)+5e^(-)rarrMn^(2)+4H_(2)O)xx2`
`(" "(2I^(-)rarrI_(2)+2e^(-))xx5)/(2MnO_(4)^(-)+16H^(+)+101^(-)rarr2Mn^(2+)+8H_(2)O+5I_(2)`
(ii) Acidified `KMnO_(4)` Oxidises `Fe^(2+)` to `Fe^(3+)`
`MnO_(4)^(-)+8H^(+)+5e^(-)rarrMn^(2+)+4H_(2)O`
`(" "(Fe^(2+)rarrFe^(3+)+e^(-))xx5)/(MnO_(4)^(-)+8H^(+)+5Fe^(2+)rarrMn^(2+)+5Fe^(3+)+4H_(2)O)`
(iii) Acidified `KMnO_(4)` oxidises `H_(2)S` to S
`(MnO_(4)^(-)+8H^(+)+5e^(-)rarrMn^(2+)+4H_(2)O)xx2`
`(" "(H_(2)Srarr2H^(+)+2e^(-)+S)xx5)/(2MnO_(4)^(-)+6H^(+)+5H_(2)Srarr2Mn^(2+)+8H_(2)O+5S)`
(iv) Acidified `KMnO_(4)` oxidises oxalate ion or oxalic acid to `CO_(2)` at 333K
`(MnO_(4)^(-)+8H^(+)+5e^(-)rarrMn^(2+)+4H_(2)O)xx2`
`(" "(C_(2)O_(4)^(2-)rarr2CO_(2)+2e^(-))xx5)/(2MnO_(4)^(2-)+16H^(+)+5C_(2)O_(4)^(2-)rarr2Mn^(2+)+8H_(2)O+10CO_(2))`