Standard reduction half-cell potentials at 25C Use tabulated standard electrode
ID: 1063584 • Letter: S
Question
Standard reduction half-cell potentials at 25C
Use tabulated standard electrode potentials to calculate the standard cell potential for the reaction occurring in an electrochemical cell at 25 C. (The equation is balanced.)
3Ni2+(aq)+2Cr(s)3Ni(s)+2Cr3+(aq)
Express your answer to two significant figures and include the appropriate units.
Half-reaction E (V) Half-reaction E (V) Au3+(aq)+3eAu(s) 1.50 Fe2+(aq)+2eFe(s) 0.45 Ag+(aq)+eAg(s) 0.80 Cr3+(aq)+eCr2+(aq) 0.50 Fe3+(aq)+3eFe2+(aq) 0.77 Cr3+(aq)+3eCr(s) 0.73 Cu+(aq)+eCu(s) 0.52 Zn2+(aq)+2eZn(s) 0.76 Cu2+(aq)+2eCu(s) 0.34 Mn2+(aq)+2eMn(s) 1.18 2H+(aq)+2eH2(g) 0.00 Al3+(aq)+3eAl(s) 1.66 Fe3+(aq)+3eFe(s) 0.036 Mg2+(aq)+2eMg(s) 2.37 Pb2+(aq)+2ePb(s) 0.13 Na+(aq)+eNa(s) 2.71 Sn2+(aq)+2eSn(s) 0.14 Ca2+(aq)+2eCa(s) 2.76 Ni2+(aq)+2eNi(s) 0.23 Ba2+(aq)+2eBa(s) 2.90 Co2+(aq)+2eCo(s) 0.28 K+(aq)+eK(s) 2.92 Cd2+(aq)+2eCd(s) 0.40 Li+(aq)+eLi(s) 3.04Explanation / Answer
3Ni2+(aq)+2Cr(s)3Ni(s)+2Cr3+(aq)
E0 Cell = E cathode - E anode
E0 Cell = E Ni+2/NI - E Cr/Cr+3
E0 Cell = 3(-0.23) - 2(-0.73)
E0 Cell = +0.77 V