Question

Which statement regarding reduction potentials is false? a. The reference standard for them is H++e–⟶12H2. b. They can be used to calculate free‑energy changes. c. They are usually tabulated as half‑reactions. d. Reactions with positive standard reduction potentials are oxidation reactions.

Answer 1

Answer:

The false statement is: d. Reactions with positive standard reduction potentials are oxidation reactions

Explanation:

Reduction potential, also called Redox potential of a species, suggests the ability of a given species to get oxidized or reduced by losing or gaining electrons.

A species with greater or more positive standard reduction potential has a greater tendency to get reduced. Thus reduction half cell reactions have a positive standard reduction potential.

The standard redox potentials for the half reactions of various chemical species are given in a tabular form and can be determined by using a reference standard hydrogen electrode (SHE), having a fixed standard electrode potential (E₀) of 0 volts.

The half cell reaction for SHE: 2 H⁺(aq) + 2 e⁻ → H₂(g)

The half cell standard potential (E₀) can be used to calculate the change in the standard Gibb's free energy (ΔG°), by the equation:

ΔG° = - n.F.E₀