Question

half-reaction | e° (v) a⁺ + e⁻ → a | -0.5 b⁺ + e⁻ → b | 0.0 c⁺ + e⁻ → c | +1.0 which substance is most likely to be oxidized from this data set? substance a substance b they are all equally likely to be reduced. substance c

Explanation:

To determine which substance is most likely to be oxidized, we use the concept of standard reduction potentials ($E^\circ$). A lower (more negative) $E^\circ$ for the reduction half - reaction means that the reverse reaction (oxidation) is more favorable.

• For the half - reaction $\ce{A+ + e- -> A}$, $E^\circ=- 0.5\space V$.
• For $\ce{B+ + e- -> B}$, $E^\circ = 0.0\space V$.
• For $\ce{C+ + e- -> C}$, $E^\circ=+ 1.0\space V$.

Since the reduction potential of A is the lowest (most negative), the oxidation of A (the reverse of $\ce{A+ + e- -> A}$, which is $\ce{A -> A+ + e-}$) is the most favorable among the three substances.

Answer:

Substance A