Chemistry HW help

Question

You are shown a voltaic cell in which the cathode is Cu and the anode is an unknown metal, X. You measure E°(cell) to be 0.74

V. The cell reaction is X(s) + Cu2+(aq) -> X2+(aq) + Cu(s). The standard reduction potential for the half-cell Cu2+ (aq)/Cu(s) is +0.34 V. Salts of both metals are in their standard states of 1.00 M concentration. Calculate the standard reduction potential of the metal X.

Answer 1

X(s) + Cu²⁺⁽aq) ==> Cu(s) + X²⁺(aq)

X is being oxidized, so is the anode

C²⁺ is being reduced so Cu is the cathode

Eºcell = reduction potential cathode - reduction potential anode

0.74 = 0.34 - ?

? = -0.40 V = standard reduction potential for X