Which of the following best describes how a fuel cell differs from electrolysis?

• A. A fuel cell converts chemical energy into electrical energy, while electrolysis uses electrical energy to drive a non-spontaneous chemical reaction.
• B. A fuel cell requires an external power source, whereas electrolysis generates electricity spontaneously.
• C. Electrolysis and fuel cells both require the same reactants and products.
• D. Both fuel cells and electrolysis produce electrical energy from chemical reactions.

Answer: (A)

Verified step by step guidance

1. Understand the fundamental processes involved in both fuel cells and electrolysis. A fuel cell is a device that converts chemical energy directly into electrical energy through a spontaneous redox reaction.
2. Recognize that electrolysis is the opposite process: it uses electrical energy to drive a non-spontaneous chemical reaction, meaning it requires an external power source to proceed.
3. Compare the energy flow in both systems: in a fuel cell, chemical energy is the input and electrical energy is the output; in electrolysis, electrical energy is the input and chemical changes occur as the output.
4. Analyze the given answer choices by matching them with these definitions. The correct description should highlight that fuel cells generate electricity from chemical reactions spontaneously, while electrolysis consumes electricity to cause chemical changes.
5. Conclude that the best description is: 'A fuel cell converts chemical energy into electrical energy, while electrolysis uses electrical energy to drive a non-spontaneous chemical reaction.' This captures the key difference in energy conversion direction.