I\'m trying to create an activity series based on experiments performed in lab.
ID: 890065 • Letter: I
Question
I'm trying to create an activity series based on experiments performed in lab. I added solid copper turnings to .05M I2 methanol to see if a redox reaction would occur between Cu and I2. To test if one did, I poured off some of the liquid phase and added 0.1M AgNO3, and a yellow AgI precipitate occured indicating an iodide ion was formed. I then tested another sample of liquid phase for a copper ion by adding 6M NH3 to check for a blue Cu(NH3)42+ complex, but there was no color change or indication of a copper ion having formed.
I guess my question is - how did iodine get reduced and become an ion if it didn't get an electron from copper? How would that net ionic equation even look? Does this make iodine the more active element? Or should there have been a copper cation that I failed to create/detect? What is going on!?
Explanation / Answer
The reaction should look like
Cu + I2 -----> CuI2 which further get converted to CuI2 ------> Cu2I2
which doesnot show color.. BLue color is due to Cu2+ and not due TO Cu+1
The iodine gets electron from coppper.