what would you see if a lot of powdered iron was added to a small amount of copper sulphate solution?

Answer 1

I'll first give a simple reaction.
Fe + CuSO4 --> FeSO4 + Cu.
This reaction precipitates copper metal. You will also see the disappearance of the bright blue color of CuSO4.

This particular reaction is complicated by the fact that both Cu and Fe have multiple possible oxidation states, which means multiple reactions are possible.

A more complicated example would be
Fe --> Fe+3 + 3e-
Cu2+ + e- --> Cu+

Fe + 3Cu+2 --> Fe+3 + 3Cu+.
In this case you won't see a precipitate, but a colored solution. I can't predict the color of this solution, because Cu+ and Fe+3 have different colors.

Furthermore, your question seems to imply a large excess of powdered iron, which means you will still have some powdered iron sitting at the bottom.

Fe + 3CuSO4 -->

Answer 2

smoke