Firstly, we need to clarify that there is no chemical substance with the formula Fe2S2O6 in reality. This formula does not comply with the unification rule of chemical elements and does not reflect any known chemical compound.
However, for the purpose of teaching students how to read and understand chemical formulas, we can assume that Fe2S2O6 is a complex organic compound consisting of iron (Fe), sulfur (S) and oxygen (O), with 2 atoms of iron, 2 atoms of sulfur, and 6 atoms of oxygen.
If we assume this substance exists, it would have vastly different physical and chemical properties depending on the molecular structure and the bonds between the atoms. Its state, color, smell, PH level,… all need to be determined through chemical experiments.
The related chemical equations are also very complicated and need to be determined based on the chemical properties of this substance. Regrettably, as there are no actual compounds matching the Fe2S2O6 formula, we cannot provide specific examples regarding reactions with metals, acids, non-metals or salts.
As for synthesis, similar to the points above, we cannot determine how to synthesize this substance in a lab or industry setting because it does not exist in reality.