1. Permanganate   IO   MnO4   SCN   O2   Hint Half-n-half Clue   2. Chromate   CrO4   IO   ClO4   SCN   Half-n-half Clue   3. Dihydrogen Phosphate   SCN   ClO   H2PO4   PO3   Half-n-half Clue   4. Dichromate (Cr2O7)   ClO3   BrO4   Cr2O7   C2O4   Half-n-half Clue   5. Cyanide   CN   BrO4   H2PO4   O2   Half-n-half Clue   6. Acetate   ClO3   BrO   SCN   C2H3O2   Half-n-half Clue   7. Perchlorate   ClO4   BrO4   IO4   ClO2   Half-n-half Clue