AP Chemistry

Reaction Stoichiometry (Chapter 4) Oxidation-Reduction/Electrochemistry

Figure 1.Electrochemical cell for the reaction between zinc and copper.

  1. Refer to the electrochemical cell above and the table of reduction potentials in answering the following questions.
  2. Using the table of reduction potentials, determine which metal ion (Zn2+ or Cu2+) is more likely to be reduced in the presence of the other’s metal (Zinc or Copper). Write the balanced net ionic equation for the reaction that would occur.
  3. Based on your answer to 1a, sketch the direction of electron flow in the diagram above. In order for positive (or negative) charges not to build up in either of the half cells, aqueous ions must flow through the salt bridge. This keeps the charge balanced. Identify which ions, and sketch the direction of the flow of those ions through the salt bridge.
  4. Based on your answers above, identify the electrode (zinc or copper) that should grow in size. Explain.
  5. 6.5 grams of zinc metal reacts with 50.00 mL of 1.50 M copper (II) solution.
  6. Calculate the limiting reactant.
  7. Calculate the theoretical yield of copper metal formed.
  8. Assuming this reaction were to take place in a beaker, describe the observations you would expect, and describe the laboratory process you would follow to recover the copper metal product.
  9. Now consider the redox reaction between lead (most common ion is 2+) and aluminum.
  10. Use the table of reduction potentials, and repeat question 1a for this reaction.
  11. Sketch and label a correct electrochemical cell (like in Figure 1) for the lead-aluminum reaction. Include the flow of electrons and ions through the salt bridge.
  12. Answer question 1c for this reaction.
  13. Create your own questions following the format of question 1d I and 1d ii. Use different values. Solve the questions you created.