List the following reducing agents in order of increasing strength under standard-state conditions: Al(s), Pb(s), Fe(s).

Verified step by step guidance

1. Step 1: Understand that a reducing agent is a substance that donates electrons in a redox reaction, causing another substance to be reduced.
2. Step 2: Recognize that the strength of a reducing agent is related to its ability to lose electrons, which can be determined by its standard reduction potential (E°).
3. Step 3: Look up the standard reduction potentials for the given metals: Al(s), Pb(s), and Fe(s). These values are typically found in a table of standard reduction potentials.
4. Step 4: Note that the more negative the standard reduction potential, the stronger the reducing agent, because it indicates a greater tendency to lose electrons.
5. Step 5: Arrange the metals in order of increasing strength as reducing agents by comparing their standard reduction potentials, from the least negative to the most negative value.