Question

which statement, a, b, or c is accurate? use the table of reduction potentials to help you. a. co₂ would make a great electron acceptor because it requires so much energy to be reduced. b. hydrogen is a very good energy source for those that can use it. c. water would be a fantastic electron donor as its oxidation yields so much energy. d. none of a,b,c are accurate – all are false!

Explanation:

To determine the accurate statement, we analyze each option:

• Option A: \( \text{CO}_2 \) as an electron acceptor. For a substance to be a good electron acceptor, its reduction should release energy (favorable). The reduction of \( \text{CO}_2 \) (e.g., in photosynthesis or some redox reactions) often requires energy input (unfavorable in many cases where energy yield is considered), so it does not "require so much energy to be reduced" in a way that makes it a great electron acceptor for energy - yielding processes. In fact, substances that release energy upon reduction are better electron acceptors for energy production.
• Option B: Hydrogen as an energy source. Hydrogen has a high energy content per unit mass. When hydrogen is oxidized (e.g., in fuel cells or combustion), it releases a large amount of energy. So hydrogen is a very good energy source for those that can use it (like in fuel - cell vehicles, industrial processes), this statement is accurate.
• Option C: Water as an electron donor. The oxidation of water (releasing electrons) in processes like photosynthesis (the oxygen - evolving complex) requires a large amount of energy input (from light energy in photosynthesis). The oxidation of water does not yield a large amount of energy; instead, it requires energy. So the statement that water "would be a fantastic electron donor as its oxidation yields so much energy" is false.

Answer:

B. Hydrogen is a very good energy source for those that can use it.