We’re being asked which of the given species has the greatest tendency to lose electrons and which is a stronger oxidizing agent.
Species that lose electrons are reducing agents. Reducing agents are the species that are being oxidized in a redox reaction.
Substances that gain electrons are oxidizing agents. The oxidizing agent is the species that are being reduced in a redox reaction.
Recall the mnemonics LEORA GEROA.
The stronger reducing agent would be the species that would be easily oxidized or easily loses an electron:
In the reaction: pyruvate + NADH + H + ⇌ lactate + NAD +: the standard reduction potentials of NAD+/NADH and private/lactate redox pairs are 0.32 V and -0.19 V respectively.
a) Which redox pair has the greatest tendency to loose electrons (breifly explain)? Which is the stronger oxidizing agent (breifly explain)?
b) If 1 M of each reactant and product are present at pH 7, which direction will the reaction proceed? why?
c) Calculate ΔG° at 25°C and pH 7 for the reaction. Is the reaction spontaneous?