Question

half-reaction | e° (v)
a⁺ + e⁻ → a | -0.5
b⁺ + e⁻ → b | 0.0
c⁺ + e⁻ → c | +1.0
which substance acts as the standard in this data set?
substance c
substance a
substance b
they are all equally likely to be reduced.

Explanation:

In standard reduction potential (E°) data, the standard hydrogen electrode (SHE) is often the reference with E° = 0.0 V. Here, the half - reaction for \(B^{+}+e^{-}\to B\) has \(E^{ \circ}=0.0\) V, which is consistent with the standard reference potential. So substance B acts as the standard here.

Answer:

Substance B