The reduction reaction based on values in the standard reduction potential table O Ubiquinone will be reduced .Therefore , O Ubiquinone will be reduced is correct.
In a redox reaction, electrons are transferred from one substance to another.
The substance that loses electrons is oxidized, while the substance that gains electrons is reduced.
The standard reduction potential (E°) is a measure of the likelihood of a substance being reduced. A more positive E° value indicates a higher tendency to be reduced.
In this case, the standard reduction potential for ubiquinone is +0.04 V, and for acetaldehyde, it is -1.23 V.
The more positive E° value for ubiquinone signifies a greater likelihood of reduction compared to acetaldehyde.
Thus, in the coupling of these reactions:
Ubiquinone + 2H+ + 2e- <=> ubiquinol
Acetaldehyde + 2H+ + 2e- <=> ethanol
Ubiquinone will undergo reduction to ubiquinol, as it has the more positive E° value, while acetaldehyde will undergo oxidation to ethanol.
The reduction reaction involves the gain of electrons and is more favorable for the substance with the higher standard reduction potential, which, in this case, is ubiquinone.