State the direction of the electron flow in the electrochemical cells represented by the following pairs of half-equations. Use the data in Appendix 2  to help you.

a. F₂ + 2e^– ⇌ 2F^– and Mn²⁺ + 2e^– ⇌ Mn

b. Sn⁴⁺ + 2e^– ⇌ Sn²⁺ and I₂ + 2e^– ⇌ 2I^–

c. Cr₂O₇^2– + 14H⁺ + 6e^–  ⇌ 2Cr³⁺ + 7H₂O and Cu²⁺ + 2e^– ⇌ Cu

d. Ni²⁺ + 2e^– ⇌ Ni and Fe³⁺ + 3e^– ⇌ Fe

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Selected standard electrode potentials Electrode reaction Electrode reaction Ag+ +e- Ag Mn2 + 2e- Mn +0.80 -1.18 Br, + 2e= 28r Mno, + 8H* + 5e = Mn2* + 4H,0 +1.07 +1.52 Ca + 2e Ca -2.87 Ni2+ + 2e- Ni - 0.25 NO, +2H* +e= NO, + H,0 +0.81 Cl, + 2e 2CH +1.36 CIO +H,0+ 2e- Cr + 20H NO, +10H" + 8e"- NH,+ 3H,0 +0.89 +0.87 Cr* + 2e Cr -0.91 0, +4H* + 4e 2H,0 +1.23 Cr+ 30 Cr 0,+ 2H,0+ 4e- 4OH -0.74 +0.40 Cr,0,+14H" + 6e= 20r* + 7H,0 +1.33 Pb2 + 2e Pb -0.13 Cu* +e Cu +0.52 Pbo, + 4H* + 2e 1 Pb* + 2H,0 +1.47 Cu2- +e Cut +0.15 Sn2* + 20 Sn -0.14 Cu + 20 Cu +0.34 Snt + 2e Sn +0.15 so + 4H* + 2e so, + 2H,0 F,+2e= 2F +2.87 +0.17 s,0,-+2e- 250, 5,0,2 + 2e= 25,0, Fe2 + 20 Fe -0.44 +2.01 Fe++e- Fe2+ +0.77 +0.09 Fe*+3e Fe -0.04 V+ 2e- V -1.20 2H* + 2e H, V3-+e V -0.26 0.00 2H,0 + 2e- H, + 20H VO2 + 2H* +e = + H,0 -0,83 +0.34 H,0, + 2H* + 2e 2H,0 vo,+ 2H* +e vo+H,0 +1.77 +1.00 1+ 2e 21- vo, + 4H* +e vo+ + 2H,0 +1.00 +0.54 K*+e-K -2.92 Zn + 2e Zn -0.76 Mg + 2e- Mg -2.38