Dilute acidified dichromate(VI) ions can oxidise ethanol to ethanal. The oxidation reaction equation is $\text{C}_2\text{H}_5\text{OH} \rightarrow \text{C}_2\text{H}_4\text{O} + 2\text{H}^+ + 2e^-.$ The reduction reaction equation is $\text{Cr}_2\text{O}_7^{2-} + 14\text{H}^+ + 6e^- \rightarrow 2\text{Cr}^{3+} + 7\text{H}_2\text{O}.$ Which of these equations is correct?
- A$\text{Cr}_2\text{O}_7^{2-} + 8\text{H}^+ + 3\text{C}_2\text{H}_5\text{OH} \rightarrow 2\text{Cr}^{3+} + 7\text{H}_2\text{O} + 3\text{C}_2\text{H}_4\text{O}$
- B$\text{Cr}_2\text{O}_7^{2-} + 12\text{H}^+ + \text{C}_2\text{H}_5\text{OH} \rightarrow 2\text{Cr}^{3+} + 7\text{H}_2\text{O} + \text{C}_2\text{H}_4\text{O}$
- C$\text{Cr}_2\text{O}_7^{2-} + 12\text{H}^+ + 3\text{C}_2\text{H}_5\text{OH} \rightarrow 2\text{Cr}^{3+} + 6\text{H}_2\text{O} + 3\text{C}_2\text{H}_4\text{O}$
- D$\text{Cr}_2\text{O}_7^{2-} + 14\text{H}^+ + 3\text{C}_2\text{H}_5\text{OH} \rightarrow 2\text{Cr}^{3+} + 6\text{H}_2\text{O} + 3\text{C}_2\text{H}_4\text{O}$