H Chemistry Review Electrochemistry

  1. In your words,
  2. Distinguish between a spontaneous and a non-spontaneous reaction.
  3. Distinguish between a galvanic (voltaic) cell and an electrolytic cell.
  1. Choose two metals from a table of reduction potentials and
  2. Sketch the galvanic cell for those metals (Be sure to oxidize the correct one). Label all the features of the cell, show the direction of electron flow through the wires, and use symbols to represent each of the metal cations and the anion in solution.
  3. Write the correct balanced net-ionic equation for the oxidation-reduction reaction taking place in the cell. Calculate the cell voltage and explain the significance of the positive value for the voltage.
  1. Standard conditions for solutions are 1.0 Molar when you use data from the table of reduction potentials.
  2. Write a “Keq” expression for your reaction in 2b above (Remember, solids are not included in equilibrium expressions) and solve for Keq.
  3. Assume that we increase the concentration of the metal ion solution that isreduced to 1.5 Molar.
  4. Write a “Q” expression and solve for “Q.”
  5. Based on your value for Q, what direction should the reaction shift? What affect will this have on the voltage?
  6. Explain how your answer above is consistent with Le Chatlier’s principle.
  7. Voltage (E) is related to equilibrium through the equation: E ≈ Eo - ln Q. ( Note that Eo is positive for galvanic cells). Use this relationship to calculate the expected voltage for the cell described in this problem.
  8. Assume that add an anion solution that will precipitate the metal ions from oxidation half cell.
  9. Will this change have the effect of increasing or decreasing “Q?” Justify your answer.
  10. Based on your answer above, what direction should the reaction shift? What affect will this have on the voltage?
  11. Explain how your answer above is consistent with Le Chatlier’s principle.
  1. Use the table of reduction potentials to find the half reactions for the reduction of silver +1 ions to silver metal and reduction of copper +2 ions to copper metal.
  2. Sketch the electrochemical cell for plating copper metal onto a silver electrode.
  3. Would this cell be galvanic or electrolytic? Explain.
  4. Write the correct balanced net-ionic equation for the oxidation-reduction reaction taking place in the cell. Calculate the cell voltage and explain the significance of the negative value for the voltage.