EXP 14

• GROUP A – these are the anions that will give volatile products or precipitate with HCl:

  Those that will give volatile products: CO3, S, SO3, NO2, CN, and ClO.

  That which gives a precipitate: S2O3.
• GROUP C – These are the anions which form insoluble products with AgNO3 (Silver Nitrate)in HNO3 (Nitric Acid):

  • The precipitate is soluble in 0.25 M NH4OH: Cl and [Fe(CN)6]-3 ,(Ferricyanide).
  • The precipitate is insoluble in 0.25 M NH4OH: Br, I, SCN, CN, and [Fe(CN)6]-4, (Ferrocyanide).
• GROUP D – These are the anions that will reduce Fe+3 to Fe+2 in acidic solution, and when [Fe(CN)6] -3 is added, a dark-blue precipitate of Fe3[Fe(CN)6]2 – Ferrous Ferricyanide is formed:

  SO3, I, S, S2O3, and NO2.
• GROUP E – These are the anions that will oxidize the pink solution of MnCl2 to brown solution of MnCl3: 


  CrO4, NO3, NO2, ClO, ClO3, and [Fe(CN)6]-3.
• GROUP F – These are the “soluble” group: ClO3, NO3, NO2, C2H3O2, and MnO4.
• Class A is subdivided into (1) gases evolved with dilute hydrochloric acid

  (HCl) or dilute sulfuric acid, (2) gases or vapors evolved with concentrated sulfuric acid (H2SO4).
• Class B is subdivided into (1) precipitation reactions, and (2) oxidation and reduction in solution.
• GROUP B – These are the anions which form insoluble products with CaCl2 or BaCl2:

  • Those that precipitate with CaCl2 in HAc (Acetic acid): C2O4, F, and SiO3.
  • Those that precipitate with BaCl2 in HAc (Acetic acid): CrO4, and SO4.
  • Those that precipitate with BaCl2 in NH4OH (Ammonium Hydroxide): PO4, AsO4, AsO4, and BO2 or BO3