[" 11."KMnO_(4)" acts as an oxidising agent in acidic medium.The "],[" number of moles of "KMnO_(4)" that will be needed to react "],[" with one mole of sulphide ions in acidic solution is : "],[[" (a) "(2)/(5)," (b) "(3)/(5)],[" (c) "(4)/(5)," (d) "(1)/(5)]]