What is the E value for the Galvanic cell formed from these two half-reactions at these concentrations? Cd2*(aq) + 2e = Cd(s); [Cd2*]= 0.50 M Mg2*(aq) + 2e = Mg(s) ; [Mg2"] = 2.75 M E° = -0.403 V E0 = -2.37 V a. 1.99 V O b. 1.90 V Oc. 1.95 V O d. 2.20 V

Which statement is true regarding the galvanic cell in which an electric current is being produced? Zn²* + 2e¯→Zn E° = -0.76 V Cu2* + 2e¯→Cu E° = +0.34 V V Salt Bridge Zn - Cu ZnSO«(aq) CUSO:(aq) (A) Oxidation occurs at the copper electrode. (B) The mass of the copper electrode is increasing. (C) Zinc ions are produced at the copper electrode. (D) Copper ions are produced at the copper electrode.

Calculate the concentration of an unknown solution in a concentration cell. A concentration cell consisting of two hydrogen electrodes (P H2- latm), where the cathode is a standard hydrogen electrode and the anode solution has an unknown pH, has a cell voltage of 0.193 V. What is the pH in the unknown solution? Assume the temperature of the solutions is 298 K. !! pH =

Questions 20 and 21 refer to the following information. Galvanic Cell Cell Diagram E°cell (Volts) Mg | Mg2(1.0 M) || Pb*2(1.0 M) | Pb 1 2.24 Zn | Zn(1.0 M) || Pb*2(1.0 M) | Pb 2 0.63 Mg | Mg*(1.0 M) || Zn*2(1.0 M) | Zn 3 The chemical reaction occurring in first galvanic cell is: Mg + Pb*2 → Mg+2 + Pb 21. If the concentration of Mg+2 is changed from 1.0 M to 3.0 M in the galvanic cells above, what will happen to the observed cell voltages in galvanic cells 1 and 3? (A) The voltage in both galvanic cells 1 and 3 will increase. (B) The voltage will decrease in both galvanic cells 1 and 3. (C) The voltage in galvanic cell 1 will increase and will decrease in galvanic cell 3 (D) The voltage in galvanic cell 3 will increase and will decrease in galvanic cell 1. 22. Consider a voltaic cell based on these half-cells. Ag (aq) +e → Ag/s) Cd (aq) + 2e → Cd¢s) E* = +0.80 V E = -0.40 V Identify the anode and give the voltage of this cell under standard conditions. (A) Ag; Ecell = 0.40 V (B) Ag;…

Consider the following voltaic cellat 25°C: Al(s) | Al3*(0.20 M, aq) || Al3+(0.75 M, aq) | Al(s) If the standard reduction potential for the Al3+(aq) /Al(s) redox couple is -1.66 V, what is the overall cell reaction and the cell potential of the voltaic cell shown above? (Reference the cell as written above.) The overall cell reaction is Al3+(0.75 M, aq) AIS*(0.20 M, ag) and E°cell = +0.0113 V. There is no overall cell reaction and E°cell = 0.00 V. The overall cell reaction is Al3+(0.20 M, aq) Als*(0.75 M, aq) and E°cell = +0.0113 V. The overall cell reaction is Al3+(0.20 M, aq) →A13+(0.75 M, ag) and E°cell| = -0.0113 V. The overall cell reaction is Al3*(0.75 M, aq) →AI3*(0.20 M, aq) and E°cell = -0.0113 V. None of these

5. A more complex example where other atoms are involved. Balance the following reaction in basic solution. r (aq) + MnO4 (aq) MnO, (s)+ BrO;" (aq) TABLE 19.1 Standard Electrode Potentials at 25 °C Reduction Half-Reaction E'(V) F + 20 H,0,(aq) + 2 H(aq)+2 e 2F(aq) 2.87 Stronger oxidizing agent Weaker 2 H,0 - PBSO (s) +2 H,0) -Mn0(s)+ 2 H,0) Mn (aq) 4 H,O) - Auts) 1.78 reducing agent PO,(s) + 4 H"(ag) + S0,2-(aq) + 2 e 1.69 Mno, (aq)+ 4 H'(aq) 3 e Mno, (aa) + 8 H (aq)+5 e Au (aq)+3e PbO,(s)+ 4 H(aa) + 2 e Cl,(g) + 2 e" 1.68 1.51 1.50 1.46 - P (ag) + 2 HO - 2a(aq) 1.36 1.33 Cr0, (aq) + 14 H'(ag) + 6 e 0+ 4 H (aq) + 4 e MnO(s)+4 H'(aq) +2 e 10, (aq) 6 H'(aq) + 5e Br+2e vo, (aq) + 2 H'(aq) + e NO, (aq) + 4 H°(aq) + 3e CIO+e 2 C"(aq) + 7 H,On - 2 H,O1) 1.23 Mn (aq) + 2 HyOV) 121 ulae) + 3 H,0() 2 Br (ag) - vo"(aq) +H,00 - NO + 2 H,O0 - CIO, (aa) - Agis) 1.20 1.09 1.00 0.96 0.95 Ag"(aa) + e 0.80 Fe (aq) + O+2 H'(aq)+2e - Fe*(aq) 0.77 - H,O,(ag) 0.70 Mn0, Taa) + e Mn0 (aa) 0.56 8) + 2 e…

Using the standard reduction potentials here, calculate the standard potential for the following cell in V (make sure you don't round your answer): Culs)Cu2"(aq)||Mn2 (aq).H"(aq)|MnO2(s)Pt(s) Your Answer:

A voltaic cell is constructed with two silver electrodes, where the half-reaction isAg2+(aq) + 2e- → Ag (s)   E° = -0.322 VDetermine the cell emf at 25 °C when the concentrations of chloride ion in the two compartments are 4.0 Mand 0.050 M, respectively.