The chemical equation Cu + 2Na2S2O4 -> CuS2O4 + 2Na2SO4

1. Detailed information about the chemical equation Cu + 2Na₂S₂O₄ -> CuS₂O₄ + 2Na₂SO₄:

   • This is a chemical equation that describes the reaction process between copper (Cu) and sodium thiosulfate (Na₂S₂O₄) to form copper thiosulfate (CuS₂O₄) and sodium sulfate (Na₂SO₄).

2. Reaction conditions:

   • This reaction requires the presence of sufficiently high temperature and pressure to initiate the reaction process.

3. Reaction process:

   • First, copper reacts with sodium thiosulfate to form an intermediate form of copper thiosulfate.
   • Then, this intermediate form reacts with sodium thiosulfate again to form copper thiosulfate and sodium sulfate.

4. Occurring phenomenon:

   • When the reaction takes place, you will see the color of the mixture change. The copper initially has a brown-red color, but when it reacts with sodium thiosulfate, the color of the mixture will turn to blue due to the formation of the copper thiosulfate compound.
   • In addition, immediately after the reaction, you can also see the generation of gases, this is a sign indicating that the chemical reaction process is taking place.

Note: The above equation may not be correct because copper thiosulfate (CuS₂O₄) is not an actual compound, and ultimately it will surely form SO₄ 2- instead of S₂O₄ 2-. Therefore, the correct equation could be: Cu + 2Na₂S₂O₃ -> CuS + 2Na₂SO₄.