J.R. S. answered 05/05/21
Ph.D. in Biochemistry--University Professor--Chemistry Tutor
K(s) ==> K+ + e- is the anode (oxidation)
Cr3+ + 3e- ==> Cr(s) is the cathode (reduction)
Looking up standard reduction potentials for each, I find the following:
K+ + e- ==> K Eº = -2.92 V
Cr3+ + 3e- ==> Cr Eº = -0.74 V
Eºcell = Cathode - Anode = -0.74 - (-2.92) = 2.18 V