Electrode Potentials and Voltaic Cells For each of the following; Write the overall cell reaction/ cell representation Calculate the standard cell potential (Eo) Determine whether the reaction is spontaneous or non-spontaneous. Ca(s)  +  Cu+2(aq)  → Cu(s)  +  Ca+2(aq) 2 Br-(aq)  +  Sn+2(aq)  → Br2(l)  +  Sn(s) 2 Ag(s)  +  Ni+2(aq)  → 2 Ag+(aq)  +  Ni(s)

Consider the voltaic Cell shown below. Voltaic Cell V Voltmeter Salt Ag (s)-> bridge Cd (s) Ag+ (aq) 2.75 M Cd+2 (aq) 0.0125 M • What is the value of potential for the spontaneous reaction that occurs as the cell operates at 25°C? Ecell = • As the cell operates spontaneously under these conditions, which electrode is the cathode of the cell? Cd Ag • Which Electrode loses mass as the cell operates under these conditions? Ag Cd

4. Write the overall balanced equation for the spontaneous process occurring in the following cell. (Hint: this is the combination of two half-reactions. One is a reduction half-reaction, and the other is an oxidation half-reaction.) Then, calculate the standard potential, E°, for the cell. Zn (s) | Zn *2 (aq) || Cu +2 (aq) | Cu (s)

4. For the following redox reaction in a galvanic cell, write the oxidation half-reaction and the reduction-half reaction, and calculate the standard cell potential of the reaction. Use Table 1 from the background as needed. Explain how you identified which substance was oxidized and which was reduced. Show all of your work. Redox reaction: Cu(s) + 2 Fe* (aq) → Cu?+ (aq) + 2 Fe* (aq) Table 1. Standard reduction potentials. Half-Reaction E°(Volts) F,(g) + 2e → 2F (aq) CI, (g) + 2e → 2CI(aq) Br, () + 2e → 2Br(aq) Ag*(aq) + e¯ → Ag(s) +2.87 +1.36 +1.07 +0.80 Fe*(aq) + e → Fe²"(aq) +0.77 Cu²*(aq) + 2e' → Cu(s) +0.34 2H*(aq) + 2e¯ → H,(g) 0.00 Fe2*(aq) + 2e' → Fe(s) -0.44 Zn*(aq) + 2e' → Zn(s) -0.76 Al³*(aq) + 3e' → Al(s) -1.66 Mg"(aq) + 2e' → Mg(s) -2.37 Ca²"(aq) + 2e" → Ca(s) -2.87 K*(aq) + e' → K(s) -2.93 В U T T O Word(s)

Please answer the follow up question

What is the overall reaction for the following cell line notation of a galvanic cell? Al(s)|AI3*(aq) || H*(aq) |H2(g)|Pt(s) 2H2(g) + Al3+*(aq) + Pt(s) → Al(s) + PtH4(s Al(s) + 3H*(aq) + Pt(s) → AI3+(aq) + PtH3(s) 3H2(g) + 2AI3*(aq) → 6H*(aq) + 2AI(s) 2AI(s) + 6H*(aq) → 2AI3+(aq) + 3H2(g 2A13+(aq) + 6H*(aq) → 3H2(g) + 2Al(s)

3 Co(s) + 2 NO 3- (aq) + 8 H+ (aq) = 3 Co 2+ (aq) + 2 NO (g) + 4 H2O (l) Determine the cell potential for the reaction at a pH of 4.0 ( you will need to use the Nernst equation) Assume that all concentrations, other than that of H+, are standard.

4. For the following redox reaction in a galvanic cell, write the oxidation half-reaction and the reduction-half reaction, and calculate the standard cell potential of the reaction. Use Table 1 from the background as needed. Explain how you identified which substance was oxidized and which was reduced. Show all of your work. Redox reaction: Cu(s) + 2 Fe" (aq) → Cu?+ (aq) + 2 Fe?+ (aq) Table 1. Standard reduction potentials. Half-Reaction E°(Volts) F,(g) + 2e → 2F(aq) CI, (g) + 2e → 2CI(aq) +2.87 +1.36 Br, () + 2e → 2Br(aq) +1.07 Ag*(aq) + e¯ → Ag(s) +0.80 Fe3*(aq) + e' → Fe2*(aq) +0.77 Cu²"(aq) + 2e' → Cu(s) +0.34 2H*(aq) + 2e¨ → H,(g) 0.00 Fe2*(aq) + 2e' → Fe(s) -0.44 Zn"(aq) + 2e' → Zn(s) -0.76 Al³*(aq) + 3e' → Al(s) -1.66 Mg2 (aq) + 2e → Mg(s) -2.37 Caа" (аg) + 2е > Ca(s) -2.87 K*(aq) + e' → K(s) -2.93 B O Word(s)

Metallic magnesium can be made by the electrolysis of molten MgCl2.(a) What mass of Mg is formed by passing a current of 8.75 A through molten MgCl2 for 2.80 days? The unbalanced chemical reaction representing this electrolysis is shown below.MgCl2  Mg + Cl2 ____g of Mg is formed by this electrolysis.(b) How many minutes are needed to plate out 17.00 g of Mg from molten MgCl2 using 5.2 A current? _____minutes are needed.

[Fe3+]= 2.0×10−3 M; [Mg2+]= 3.15 M   Express your answer in units of volts.