Chemistry Forum

A voltaic cell made with Cu l CuSO₄ ll Fe l Fe(NO₃)₃ yielded a -0.420V when connected with black to Fe and red to Cu. The Cu has the lower Standard Reduction Potential(0.34V) so it should be oxidized( anode = black lead to meter) and the Fe(0.77V) should be reduced(cathode = red lead to meter) but this gives a negative voltage which means the flow of electrons( DC current is going in the opposite direction. (Both solutions were 1.0M)
This was done in "micro scale" with a black yarn string soaked in KCl as the salt bridge.
Seems weird. Any help out there?

wrong potential choosen

You choose Fe₂+ to Fe₃+ with 0,77 V

but you have Fe and Fe₃+ in your cell it has -0,036 V

between there is also Fe and Fe 2+ with -0.402 V