I have this lab question for the lab called Copper Collection Stoichiometry, where we choose an amount of the limiting reagent (iron) for a reaction between copper (II) sulfate and iron. We are to dissolve copper (II) sulfate in water, making it blue, then add iron, and after filtrating, we should have copper left.
How do we know if iron was the limiting reagent in terms of the visual observations? We made it so that iron was the limiting reagent, but how do we know visually if it is?
I understand that in order for iron to be a limiting reagent, it should've reacted with the solution and all completely turned into copper after the experiment. However how do we know if all the iron actually turned into copper? There is no way that we can visually count every solid flake to make sure there's no iron. I also understand that if iron was the limiting reagent, then there should be still copper (II) sulfate left in the solution, as the reaction didn't completely occur. Is that the answer?