7) A flow chart for the procedure follows. From step1 O NHa AI(OH)3, Fe(OH)s Zn(NH) and Group IIl Cations 7 NaOH TO HCI+ thioacetaide Fe(OH)3 ZnS Al(OH,- Group IlI lons : white 8 OHCI+ aluminon Fe3 Al* NH3 9 Al(OH)s red lake 8 KSCN FeSCN2 blood-red Solution 3. A. Definitely present- Fe 3+ ion.( as red ppt of FeSCN 2+ formed) B. Definitely Absent- Zn 2+ ( filtrate gives no white ppt on adding Sulphide ion) C. Possibly present - Al 3+ (as some amount of the ppt is soluble in NaOH) 4. A. Definitely present - none ( no confirmatory test for Zn ion has done) B. Definitely Absent - Al 3+ , Fe 3+ ( no ppt is formed) C. Possibly present - Zn 2+ (the sample is soluble in Ammonia) .