Acetylene is oxidised by permanganate in acidic solutions to liberate carbondioxide.

Explanation

(a) The ionic skeleton equation is written as
`C_(2)H_(2)+MnO_(4)^(-) overset(H^(+))to CO_(2)+Mn^(2+)`
(b) Writing oxidation numbers
`overset(-1)(C_(2)) overset(+1)(H_(2)) + overset(+7)(Mn) overset(-2)(O_(4)^(-)) to overset(+4)(C ) overset(-2) (O_(2))+overset(+2)(Mn^(+2))`
(c) Locating atoms undergoing change in oxidation numbers
`overset(-1)(C_(2)) H_(2)+overset(+7)(Mn) O_(4)^(-) to overset(+4)(CO_(2)) +overset(+2)(Mn^(+2))`
(d) Dividing the reaction into two halves and balancing in acidic medium, separately.
(d) Equilising the electrons and adding the two halves.
`eq (a) xx 1 +eq (b) xx 2,` we get
`C_(2)H_(2)+4H_(2)O to 2CO_(2)+10H^(+)+10e^(-)`
`2MnO_(4)^(-)+16H^(+)+10e^(-) to 2Mn^(2+)+8H_(2)O`
`C_(2)H_(2)+2MnO_(4)^(-)+6H^(+) to 2CO_(2)+2Mn^(2+)+4H_(2)O`
This is the balanced equation.