Several common masking agents used in EDTA titrations are listed paired with a mixture of two metal ions. Classify each masking agent-metal ion combination by whether the masking agent is capable of masking one of the metal ions and still allowing the other metal ion to react with EDTA or not. Masks one metal ion but not the other Does not mask or masks both metal ions cyanide: Zn2+ and Pd2+ cyanide: Co2+ and Mn2+ fluoride: A13+ and Fe3+ triethanolamine: A13+ and Pb2+ fluoride: Be2+ and Cu2+ triethanolamine: Fe3+ and Mn2+ Answer Bank