Oxidation-Reduction Activity Series
Exercise 1: Describing an Oxidation-Reduction Reaction
Data Table 1. Redox Reaction of Copper and Silver Nitrate.
Note:Copper has a +2 oxidation number in the products.
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Initial observations before beginning
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Copper is a reddish-brown, shiny, malleable metal and silver nitrate is a clear, colorless liquid.
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Observations
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After about one minute, the copper begins forming dark gray and black areas that look dull in appearance.
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Observations after 30 minutes
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Grayish-white crystals form on top with gray fuzzy material on bottom.
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Chemical equation
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Element that is oxidized
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Element that is reduced
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Spectator ion
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Oxidizing agent
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Reducing agent
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Questions
A. Define oxidation, reduction, and oxidation number. Describe how oxidation and reduction affect the oxidation number of an element.
B. Define oxidizing agent, reducing agent, and spectator ion.
C. In the reaction of copper and silver nitrate, a new substance appeared in the test tube. Describe the physical appearance of the substance and identify its chemical formula.
D. Given an activity series in which the most active metals are at the top of the list and the least active metals are at the bottom of the list, would copper be listed above silver or would silver be listed above copper? Support your answer with data from Data Table 1.
E. Solid copper sulfide and silver nitrate react to form copper (II) nitrate and solid silver sulfide. Write a balanced chemical equation that describes the reaction. Identify the oxidation number of each element in the reaction. (You do not need to include the total contribution of charge.) Is this reaction a redox reaction or a non-redox reaction? Explain your answer.
Exercise 2: Creating an Activity Series
Data Table 2. Redox Reactions of Copper, Lead, and Zinc.
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Solid metal
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Well ID
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Solution
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Immediate observations
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30 Minute Observations
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Cu
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A1
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Pb(NO3)2
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No noticeable change.
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No noticeable change.
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A2
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Zn(NO3)2
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No noticeable change.
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No noticeable change.
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Pb
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B1
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CuSO4
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No noticeable change.
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No noticeable change.
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B2
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Zn(NO3)2
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No noticeable change.
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No noticeable change.
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Zn
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C1
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CuSO4
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Zinc develops coppery appearance, or reddish-brown appearance.
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Large black substance with smaller, flaky looking black substances floating in solution.
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C2
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Pb(NO3)2
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Zinc becomes dark gray and starts to look fuzzy or hairy.
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Large, dark gray substance with smaller dark gray substances floating in solution.
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Data Table 3. Potential Redox Reactions and Chemical Equations.
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Metal and Metallic Solution
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Reaction Occurred?
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Chemical Equation
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Cu + Pb(NO3)2
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Cu + Zn(NO3)2
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Pb + CuSO4
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Pb + Zn(NO3)2
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Zn + CuSO4
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Zn + Pb(NO3)2
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Questions
A. List each of the metals tested in Exercise 2. Indicate the oxidation number when each element is pure and the oxidation number when each element is in a compound.
B. Which of the metals in Exercise 2 was the strongest oxidizing agent? Was there an instance when this metal also acted as a reducing agent? Explain your answer using data from Data Table 3.
C. Which of the metals in Exercise 2 was the strongest reducing agent? Was there an instance when this metal also acted as an oxidizing agent? Explain your answer using data from Data Table 3.
D. How does ease of oxidation correlate with activity? Do highly active metals tend to donate electrons or accept electrons from other metals?
E. Create an activity series for copper, lead, and zinc. Place the most active metal at the top of the list.