1 / 6

REDOX EQM Half Cells with Inert Electrode

p.01. C. Y. Yeung (CHW, 2009). M. M n+. 03. REDOX EQM Half Cells with Inert Electrode. Inert Electrode :. In the metal-metal ion system, metal is the electrode, and metal ion is the electrolyte.

drew-clay
Download Presentation

REDOX EQM Half Cells with Inert Electrode

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. p.01 C. Y. Yeung (CHW, 2009) M Mn+ 03 REDOX EQM Half Cells with Inert Electrode Inert Electrode : In the metal-metal ion system, metal is the electrode, and metal ion is the electrolyte. However, if the system does not involve metal, and “inert electrode” is required. (e.g. platinium / graphite)

  2. p.02 <Example 1> Cell Diagram as cathode: Fe3+(aq) , Fe2+(aq) | Pt(s) Fe3+(aq) + e- Fe2+(aq) as anode: Pt(s) | Fe2+(aq) , Fe3+(aq) <Example 2> = +0.77 V = +1.52 V E E MnO4-,Mn2+| Pt Fe3+,Fe2+| Pt MnO4-(aq) + 8H+ + 5e- Mn2+(aq) + 4H2O(l) Pt - e- + e- Cell Diagram FeSO4(aq) + Fe2(SO4)3(aq) Fe2+ as cathode: [MnO4-(aq) + 8H+(aq)] , [Mn2+(aq) + 4H2O(l)] | Pt(s) Fe3+ as anode: Pt(s) | [Mn2+(aq) + 4H2O(l)] , [MnO4-(aq) + 8H+(aq)] Half Cells using Inert Electrode : (1) Metal Ion – Metal Ion Sytem

  3. p.03 = +1.52 V E MnO4-,Mn2+| Pt anode cathode = +0.77 V E Fe3+,Fe2+| Pt Ecell = +1.52 – (+0.77) = +0.75V Cell Diagram Oxidation C(graphite) | Fe2+(aq) , Fe3+(aq) [MnO4-(aq) + 8H+(aq)] , [Mn2+(aq) + 4H2O(l)] | C(graphite) Reduction Exercise Calculate the cell e.m.f. and write the cell diagram of the electrochemical cell shown below in accordance with the IUPAC convention. (ref.: p. 207) [Ref.: p. 210 Example 20-5C]

  4. p.04 <Example> Cell Diagram as cathode: I2(aq) , 2I-(aq) | Pt(s) as anode: Pt(s) | 2I-(aq) , I2(aq) Exercise I2(aq) + 2e- 2 I-(aq) = +0.54 V E I2, I- | Pt Pt Ecell = +0.77 – (+0.54) = +0.23V - e- + e- I2(aq) + I-(aq) I- Cell Diagram: Pt(s) | 2I-(aq) , I2(aq) Fe3+(aq) , Fe2+(aq) | Pt(s) I2 (2) Non-metal Ion – Non-metal Ion Sytem If iron(III) / iron(II) system acts as the cathode, while iodine / iodide acts as the anode, with using platinium as electrodes. Calculate the cell e.m.f. and write the cell diagram. (ref.: p.207)

  5. p.05 <Example 1> Pt E E = -0.35 V = +0.54 V + e- PbSO4 | Pb AgCl | Ag Ag Cell Diagram - e- electrolyte! AgCl as cathode: Cl-(aq) | AgCl(s) | Ag(s) as anode: Ag(s) | AgCl(s) | Cl-(aq) <Example 2> PbSO4(s) + 2e- Pb(s) + SO42-(aq) AgCl(s) + e- Ag(s) + Cl-(aq) Platinium Black coated with Ag and AgCl Cell Diagram as cathode: SO42-(aq) | PbSO4(s) | Pb(s) HCl(aq) as anode: Pb(s) | PbSO4(s) | SO42-(aq) (3) Metal – Sparingly Soluble Salt Sytem i.e. H2SO4 is used as electrolyte.

  6. p.06 Next …. Standard Hydrogen Electrode (S.H.E.), Measurement of Standard Electrode Potentials (p. 197-212) Assignment p.202 Table 20.1…? p.202 Check Point 20.3 [due date: 11/5 (Mon)] p.20.5(b) [due date: 11/5 (Mon)]

More Related