multiple choice from 49-53
41 49. An electrochemical cell is set up with a copper electrode in contact with 1.0 mol/L CuSofa and a lead electrode in contact with 1.0 mol/L Pb(NO3)2le). The standard reduction potentials are Pb2+ + 28 Pb 2.-0.13V C++ 20 CM 2 - +0.347 At 25C, the standard cell potential for this galvanic cell in volts is d. 0.21 e. 0.94 a. 0.13 b. 0.34 c. 0.47 salt bridge 50. In the electrochemical cell above, the left half cell is set up with a zine electrode in contact with 1.0 mol/L Zn(NO3)acer and the right half-cell is set up with a silver electrode in contact with 10 mol/L AgNO3 The relevant reduction potentials are Age +e Ag -0.80 V Zn2+ + 2e n E=-0.76V Which of the following statements is false? a. the silver electrode is the cathode b. increasing the ( Zn] will increase the cell voltage c. clectrons in the external circuit will flow from zinc to silver d. the standard cell potential for this cell is 1.56 V e. the zinc electrode is the anode 51. Consider the above cell at 25C. In the left half-cell, a lead electrode is in contact with 0.10 mol/L Pb(NO3)2(ap) and in the right half-cell, a copper electrode is in contact with 0.20 mol/L CuSO.(p). The standard reduction potentials are as follows: Pb2+ + 2e PB --0.13 V CY** + 20 CM 8 - +0.34 V Which of the following statements about this cell is false? a. so-ions migrate into the left half-cell through the salt bridge b. electrons flow from the copper electrode to the lead electrode c. the cell is not at standard conditions d. Pb2+ ions migrate into the right half-cell through the salt bridge c. reduction occurs at the copper electrode 52. The following half reactions are involved in an electrochemical cell: Ag* + e - Ag E-0.80 V Zn2+ + 2e n p -0.76V The addition of sodium chloride solution, Nalep), to the silver half-cell results in the precipitation of silver chloride, AgC1. Which of the following voltage changes will occur as NaCler) is added to the silver half- cell? a. the cell voltage will decrease d. the cell voltage will not change b. the cell voltage will drop to zero c. the cell voltage will double c. the cell voltage will increase 53. This question consists of an assertion (statement) in the left-hand column and a reason in the right-hand column. Assertion Reason The voltage of an electrochemical cell does Operating an electrochemical cell changes not remain constant as electrons flow in the the concentration of ions in the half-cells external circuit which results in an increase in the cell voltage Select one of the following a if both assertion and reason are true statements, and the reason is a correct explanation of the assertion b. if both assertion and reason are true statements, and the reason is not a correct explanation of the assertion e. if the assertion is true but the reason is false d. if the assertion is false but the reason is a true statement e. if both assertion and reason are false statements
