<prompt> Compound used for water purification:KMnO4IodineChlorineCopper sulphate  <response>: Ans: c Chlorine Ref:Park, 19 ed,p. 575Xenodiagnosis is related to -trench feverEpidemiological tetrad is related to-scrub typhusChlorine:Contact period--1 hourNo effect on spores protozoal cyst needs superchlorinationEffective against all virus except polio hepatitis ABleaching powder:Iodine: Chemically CaOC12Emergency disinfection of water Available chlorine is 33Contact time 20-30 min Unstable compoundEffective over wide range of pH values Free residual chlorine needed for effective chlorination is 0.5 mg1. at the end of one hour contact period.Persist longer than chlorine 