This question is about titanium compounds and ions.
Use data from the table below to identify the species that can be used to reduce TiO2+\text{TiO}^{2+}TiO2+ ions to Ti3+\text{Ti}^{3+}Ti3+ in aqueous solution and no further. Explain your answer.
| Electrode half-equation | Eθ / VE^\theta \text{ / V}Eθ / V |
|---|---|
| TiO2+(aq)+2H+(aq)+e−→Ti3+(aq)+H2O(l)\text{TiO}^{2+}(\text{aq}) + 2\text{H}^+(\text{aq}) + e^- \to \text{Ti}^{3+}(\text{aq}) + \text{H}_2\text{O}(\text{l})TiO2+(aq)+2H+(aq)+e−→Ti3+(aq)+H2O(l) | +0.10+0.10+0.10 |
| Ti3+(aq)+e−→Ti2+(aq)\text{Ti}^{3+}(\text{aq}) + e^- \to \text{Ti}^{2+}(\text{aq})Ti3+(aq)+e−→Ti2+(aq) | −0.37-0.37−0.37 |
| Fe3+(aq)+e−→Fe2+(aq)\text{Fe}^{3+}(\text{aq}) + e^- \to \text{Fe}^{2+}(\text{aq})Fe3+(aq)+e−→Fe2+(aq) | +0.77+0.77+0.77 |
| Sn2+(aq)+2e−→Sn(s)\text{Sn}^{2+}(\text{aq}) + 2e^- \to \text{Sn}(\text{s})Sn2+(aq)+2e−→Sn(s) | −0.14-0.14−0.14 |
| Cr3+(aq)+e−→Cr2+(aq)\text{Cr}^{3+}(\text{aq}) + e^- \to \text{Cr}^{2+}(\text{aq})Cr3+(aq)+e−→Cr2+(aq) | −0.41-0.41−0.41 |
Give the oxidation state of titanium in [TiO(H2O)5]2+[\text{TiO}(\text{H}_2\text{O})_5]^{2+}[TiO(H2O)5]2+.
