The standard reduction potentials of the following halfreactions are given in Appendix E: Ag+1aq2 + e- ¡ Ag1s2 Cu2+1aq2 + 2 e- ¡ Cu1s2 Ni2+1aq2 + 2 e- ¡ Ni1s2 Cr3+1aq2 + 3 e- ¡ Cr1s2 (b) Determine which combination of these half-cell reactions leads to the cell reaction with the smallest positive cell potential and calculate the value.