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匿名
匿名 發問於 科學及數學化學 · 1 十年前

easy minimal electrochem. cell

Question 1:

Use the following list of standard reduction potentials to answer all of the Post-lab questions.

Assume a temperature of 25Celsius for all of the questions.

reaction number/ Half-reaction / ξo(V)

1F2 (g) + 2e- → 2 F-(aq) 2.87

2 Ag2+(aq) + e- → Ag+(aq) 1.99

3 PbO2(s) + 4H+(aq) + SO42-(aq) + 2e- → PbSO4(s) + 2H2O 1.69

4 MnO4-(aq) + 4H+(aq) + 3e- → MnO2(s) + 2H2O 1.68

5 Cr2O72-(aq) + 14H+(aq) + 6e- → 2Cr3+ (aq) + 7H2O 1.33

6 Fe3+(aq) + e- → Fe2+(aq) 0.77

7 O2(g) + 2H+(aq) + 2e- → H2O2(l) 0.68

8 Sn4+ (aq) + 2e- → Sn2+(aq) 0.13

9 2H+(aq) + 2e- → H2(g) 0.00

10 Pb2+ (aq) + 2e- → Pb(s) -0.13

11 Sn2+(aq) + 2e- → Sn(s) -0.14

12 PbSO4(s) + 2e- → Pb(s) + SO42-(aq) -0.35

13 Fe2+ (aq) + 2e- → Fe(s) -0.44

14 Cr3+(aq) + e- → Cr2+(aq) -0.50

15 2H2O + 2e- → H2(g) + 2OH-(aq) -0.83

16 Mn2+(aq) + 2e- → Mn(s) -1.18

17 Li+(aq) + e- → Li(s) -3.05

Describe the set-up of a minimal galvanic cell using reactions 4 and 16. Remember that minimal cells contain only the reactants necessary for the two half-reactions to proceed. Products should not be present. (Not all components need to be used and some components may be used more than once).

Fill in the correct components in the line diagram for a minimal cell. Remember, the anode is on the left and the cathode is on the right.

using :Mn(s),C(s),KNO3(aq),MnO4-(aq)/H+(aq),MnO2(s),or Mn2+(aq) to fill the the blank.

____________l______________ll___________l_________

1 個解答

評分
  • 1 十年前
    最愛解答

    Since Mn and MnO2 are under solid state, they can be used as the electrodes directly.

    Also, the overall reaction favourable should be:

    2MnO4-(aq) + 8H+(aq) + 3Mn(s) → 2MnO2(s) + 4H2O(l) + 3Mn2+(aq)

    Thus MnO2 side will be the cathode with the cell diagram:

    Mn(s) | Mn2+(aq) || MnO4-(aq), H+(aq) | MnO2(s)

    資料來源: Myself
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