2 Al + 3 Cu(NO3)2 --> 2 Al(NO3)3 + 3 Cu
1. Write balanced equations for the oxidation and reduction half-reactions. Identify each half-reaction as oxidation or reduction.
2. In the balanced overall reaction, determine which is the oxidation and reduction agent.
3. Which metal is more effective, aluminum or copper? (which one is the more active one) Show your reasoning.
To answer these questions, we can break down the given chemical equation into half-reactions and examine the changes in oxidation states.
1. Writing the balanced half-reactions:
Oxidation half-reaction: 2Al → 2Al^3+ + 6e-
This is an oxidation reaction because aluminum (Al) loses electrons and increases its oxidation state from 0 to +3.
Reduction half-reaction: 3Cu^2+ + 6e- → 3Cu
This is a reduction reaction because copper (Cu) gains electrons and decreases its oxidation state from +2 to 0.
2. Identifying the oxidation and reduction agents:
In the oxidation half-reaction, aluminum loses electrons and gets oxidized from its elemental form to Al^3+. Thus, aluminum is the reducing agent in this reaction.
In the reduction half-reaction, copper gains electrons and gets reduced from Cu^2+ to its elemental form (Cu). Hence, copper is the oxidizing agent in this reaction.
3. Determining the more active metal:
To evaluate the effectiveness of each metal, we need to consider their relative positions in the activity series. The metal higher in the activity series tends to be more effective at displacing the other metal from its compounds.
In this reaction, aluminum (Al) displaces copper (Cu) from its compounds, indicating that aluminum is more active than copper. Therefore, aluminum is the more effective metal in this scenario.
The reasoning is based on the activity series, which lists metals in order of their reactivity. The metal higher in the activity series can displace the metal lower in the series from its compounds. Aluminum is higher in the activity series than copper, which explains why aluminum reacts with copper nitrate to form aluminum nitrate and copper.