Question

1. The table at right is similar to Table 18.1 in that it tabulates standard reduction voltages of half reactions, but in this case the half reactions involve organic molecules important in biochemistry. Note here that the standard conditions are biochemically standard conditions (E^°) where T = 25 ^°C but [H⁺] = 10^-7 M (much less acidic than the [H⁺] = 1 M in Table 18.1).

Oxidized form	Reduced form	E°(V)
Glutahione (oxidized) + 2e-	-> Glutathione(reduced)	-0.23
Fumarate + 2e-	-> Succinate	0.03
Ubiquinone (oxidized) + 2e-	-> Ubiquinone (reduced)	0.10
½ O2 + 2H+ + 2e-	-> H2O	0.82

(a) Identify the strongest reducing agent from this table.

(b) Identify the strongest oxidizing agent from this table.

(c) Compare the E^° for the oxygen half reaction to the same half reaction in Table 18.1. Under which conditions, high pH or low pH is oxygen a stronger oxidizing agent?

Answer 1

A) reducing agent is the one which itself gets oxidised. Thus it is the one which has most positive oxidation potential or most negative reduction potential.

Here all reduction potentials are given, thus most negative reduction potential is of Glutahione. Thus it is strongest reducing agent.

B) strongest oxidising agent is the the one having most positive oxidation potential. From the table, most positive oxidation potential is of O2. Thus it is strongest oxidising agent

C) please provide table 18.1 for this part.