AP Chem Unit 16 HW Packet by tcX55CZ

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AP Chem Unit 16: HW Packet                                  Name:_________________________

_____/ 145pts

   1. (20pts) A cell is constructed with Cr(s) | Cr3+ || Cu2+ | Cu(s) .
         a. Write the half reaction that takes place at the anode.




          b. Write the half reaction that takes place at the cathode.




          c. Write the balanced equation for the spontaneous redox reaction that
             occurs in the cell.




          d. Calculate the standard cell potential, Eo, in volts for the spontaneous
             reaction above.




          e. What would be better to use in the salt bridge, NasSO4 or BaSO4? (Hint:
             think solubility rules)
2. (25pts) You are to construct a galvanic cell with the highest possible cell
   potential from some of the following equipment: Aluminum metal, Zinc metal,
   gold metal, salt bridge, a beaker each of 1.0M CuSO4, 1.0M ZnSO4 and 1.0M
   Au(NO3)3.
      a. Write the half reaction that takes place at the anode.




      b. Write the half reaction that takes place at the cathode.




      c. Write the balanced equation for the spontaneous redox reaction that
         occurs in the cell.




      d. Calculate the standard cell potential, Eo, in volts for the spontaneous
         reaction above.




      e. Which metal is used at the anode, and which is used at the cathode?
3. (30pts) The following reaction takes place in a acidic galvanic cell:
          O2(g) + H2S(g)  S(s) + H2O(l)
      a. Write the half reaction that takes place at the anode.




       b. Write the half reaction that takes place at the cathode.




       c. Write the balanced equation for the spontaneous redox reaction that
          occurs in the cell.




       d. Calculate the standard cell potential, Eo, in volts for the spontaneous
          reaction above.




       e. What is the total charge that passes through the cell when 0.128 moles
          of H2S are consumed.




       f. How much charge passes through a wire carrying 2.5 A of current for 16
          minutes?
4. (5pts) How many moles of electrons pass through a wire that is carrying 1.74
   A of current for 28.6 minutes?




5. (10pts) Write a balanced redox equation for the following reactions:
      a. Solid zinc is placed in a solution of lead (II) nitrate.




       b. Solid nickel is placed in a solution of copper (II) sulfate.




6. (6pts) Use the list of standard reduction potential values to indicate which
   species in each set is the strongest oxidizing agent.
      a. Sn2+(aq) or Pb2+(aq)
       b. Cu+(aq) or Cu(s)
       c. Ag+(aq) or Cu(s)



7. (6pts) Use the list of standard reduction potential values to indicate which
   species in each set is the strongest reducing agent.
      a. Li+(aq) or Li(s)
       b. Au(s) or Fe(s)
       c. Au3+(aq) or Ba(s)
8. (15pts) A galvanic cell operates through the reaction represented by
          2Ag+(aq) + Zn(s)  2Ag(s) + Zn2+(aq)
      a. What is the standard cell potential for the reaction?




      b. Find the free energy change, ΔGo, that occurs for the reaction.




      c. Is the reaction spontaneous?




9. (15pts) A cell operates through the reaction represented by
          Pb2+(aq) + Ni(s)  Pb(s) + Ni2+(aq)
      a. What is the standard cell potential for the reaction?




      b. What will happen to the voltage if the concentration of Pb2+ decreases.
         Justify your answer.




      c. Find the equilibrium constant, K, at 25o C using the Nernst Equation.
10. (8pts) How many minutes would it take to plate out:
       a. 103 g of solid nickel from a Ni2+ solution with a current of 2.75
           amperes?




       b. 125 g of solid copper from a Cu2+ solution with a current of 5.35
          amperes?




11. (5pts) If 0.4000 faradays of charge passes through a Cu2+ solution, what mass
    of solid copper can be produced?

								
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