(A) Consider a galvanic cell based on the following half-reactions. Assuming the cell operates under standard conditions at 25 °C, what is the spontaneous cell reaction? Under what nonstandard conditions is the spontaneous formation of [PtCl₆]^2– favored? Do you think that, in practical terms, a significant amount of PtCl₆^2– can be obtained by altering the concentrations in a galvanic cell?

(B) Because metallic titanium exhibits excellent corrosion resistance, it is often desirable to coat iron objects with a thin coating of titanium metal. One approach involves production of Ti(s) from electrolysis of molten mixtures of NaCl and TiCl₂. The production of Ti(s) involves the disproportionation of Ti²⁺ to Ti³⁺ and Ti. Write a balanced chemical equation for the disproportionation reaction and use the following half-reactions to decide whether the disproportionation reaction is spontaneous under standard conditions. Ti²⁺ + 2e^– → Ti, E° = –1.630 V; Ti3⁺ + e^– → Ti²⁺, E° = –0.369 V.

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PtCl² + 2 e V³+ + e PtCl² + 2 Cr V2+ Eº E° = = 0.68 V -0.255 V