1. The following oxidation and reduction half-reactions are possible for the electrolysis of potassium iodide solution. The solution contains water molecules, potassium ions (K*), and iodide ions (I-). 2H,0(1) 0,(g) + 4H*(aq) + 4e- 2H,O(1) + 2e- → H,(g) + 20H (aq) K*(aq) + e- → K(s) 21-(aq) L(s) + 2e- a. What product was formed at the anode in the electrolysis of potassium iodide solution? Explain, citing specific evi- dence from your observations. O29)+H* cael +4c-→ 2HzOce) Izca) is produced Anode the anede The confor E'ceu =+ 1.23 V product of I at by color change from Yellow to black Lobserved in the presence of starch) E'eell = to.SYV b. What product was formed at the cathode in the electrolysis of potassium iodide solution? Explain based on your observations. ZA20 1D + 2e- -> Hz lg) + 204 cag) A219) t 2014 ions are Produced k*cap)te> Kes) Hydvogen gas bubbles out from the solutio E cell = :13V and hy droxi'des turn fhe Phenolphthalein E cell = - 2.93 V to pink Solotion c. Write the balanced chemical equation for the overall redox reaction in the electrolysis of aqueous potassium iodide. Hint: Remember to balance the electrons!

+ 1.14 V TI Pt Cr3+ (1 M) Cr2 (1 M) T13+ (1 M) T13+ (aq) + 3e-→ TI (s) Cr2+ (aq) → Cr3+ (aq) + e- What happens to the thallium electrode as the redox reaction progresses? O it gains mass as thallium metal is plated onto the electrode O it loses mass as the thallium metal is consumed by the reaction O it spontaneously ignites and burns O the thallium electrode is inert and unaffected by the redox reaction O a thick layer of thallium salt develops on the clectrode DELL

12 The standard cell potential for the following galvanic cell is 0.71 V. Mg(s) Mg2+(aq)||A13+(aq)|Al This reaction has an equilibrium constant, K =

A certain metal è forms a soluble sulfate salt ₂(so). Suppose the left half cell of a galvanic cell apparatus is filled with a 5.00 M solution of M₂(SO4)3 and the right half cell with a 250. mM solution of the same substance. Electrodes made of M are dipped into both solutions and a voltmeter is connected between them. The temperature of the apparatus is held constant at 35.0 °C. Which electrode will be positive? O left Be sure your answer has a unit symbol, if necessary, and round it to 2 significant digits. O right What voltage will the voltmeter show? Assume its positive lead is connected to the positive electrode. 0 x10 X