Arrange the three metals in order of their relative strengths as reducing agents, placing the strongest first. Write each metal as a half reaction.
To determine the relative strengths of the three metals as reducing agents, we need to examine their standard reduction potentials. The metal with the most positive reduction potential will be the strongest reducing agent.
The standard reduction potential values for different metals can be found in standard electrochemical tables. These tables provide the reduction potentials for various half-reactions, which involve the reaction of a metal with its corresponding metal cation.
1. Locate the metals in the electrochemical table and find their respective half-reactions. Half-reactions usually take the form:
Metal (M) + n electrons (e-) ↔ Metal cation (M^n+)
2. Compare the reduction potentials (E°) for each half-reaction. A more positive reduction potential indicates a stronger reducing agent.
3. Arrange the metals in descending order based on their reduction potentials. The metal with the highest (most positive) reduction potential will be the strongest reducing agent.
Here are the half-reactions and the order of their relative strengths as reducing agents:
1. Strongest reducing agent:
Metal M1 + n electrons ↔ Metal cation M1^n+
2. Moderate reducing agent:
Metal M2 + n electrons ↔ Metal cation M2^n+
3. Weakest reducing agent:
Metal M3 + n electrons ↔ Metal cation M3^n+
To confirm the specific half-reactions and the order of their relative strengths, it is necessary to refer to the electrochemical table that provides the standard reduction potentials for the given metals.