Question

Consider a galvanic cell where one compartment has Br2 (aq) at a concentration of 0.50 M and Br ̄ at a concentration of 0.10 M with a platinum electrode and the second compartment has Cr3+ at a concentration of 0.20 M and a Cr electrode. Use the following reduction potentials to answer the questions:

Cr3+ (aq) + e ̄→Cr(s) εo = - 0.73 V

Br2(aq) + 2e ̄→2Br ̄ (aq) εo =1.09V
a. What is the standard cell potential for this galvanic cell?
b. What is the non-standard cell potential for this galvanic cell?

Answer 1

I → since the reduction hotential for Br, Br couple is more than that of cont3/ con couple. So, that Br / Br compartiment acts as cathote (Reduction) f +31 cor compartment acts as anote Toxitation) So At anode ir loxidation) cress - (n+3 + 3 e ] x 2 +3 16 = -1 At cathoder I Reduction) Bor, cagi) + ze 2Br J X3 E Brilby- 109V --0173 a 200 + 3 Br2 → 26+3 + Bor with Ecell = E Cathote - Eshote 109- (-0.73) E cell = 1.820 6 By Nernst eghin Ecell = E cell -0.0591 log [br] [ (n +3] n [Br] > Fell = 1.82 - 0.0591 log (0.10) x (0-203 | (o.sop - E cell = 1.82 -0.059) log (3.2x10-7) 6 =) Ecell = 1.82 +0:0591 x 6.49 = Je cell = +1.88v & Non-standaard cell potential for this cell.