A) increases. B) decreases. C) is unchanged. D) It is impossible to tell what will happen. 46. A concentration cell is constructed using two Ni electrodes with Ni2+ concentrations of 1.64 and 2.85 10–4 in the two M  M half-cells. The reduction potential of Ni2+ is V. Calculate the potential of the cell at 25°C. –0.23 A) +0.341 V B) V –0.222 C) V –0.256 D) +0.111 V E) V –0.0078 47. The standard potential for the reaction A(s) + B3+(aq) A3+(aq) + B(s) is 0.50 V. What is the equilibrium constant for this K reaction at 25°C? A) 3.1 1025  B) 3.2  10–26 C) 17 D) –17 E) 0.015 48. A concentration cell is constructed using two Co electrodes with Co2+ concentrations of 0.20 and 4.4 10–5 in the two  M M half-cells. Determine the standard reduction potential of Co2+, given that the potential of the cell at 25°C is 0.108 V. A) 0 V B) +0.108 V C) V –0.108 D) +0.216 V E) This cannot be determined with the information given. Use the following to answer question 49: Consider the galvanic cell shown below (the contents of each half-cell are written beneath each compartment). The standard reduction potentials are as follows: Cr3+ + 3e– Cr(s) = V  E° –0.73 = +1.09 V Br2(aq) + 2e–  2Br– E° 49. What is the value of for this cell at 25°C? E A) 2.21 V B) 1.76 V C) 2.12 V D) 1.88 V E) 0.59 V Use the following to answer question 50: Consider an electrochemical cell with a copper electrode immersed in 1.0 Cu2+ and a silver electrode immersed in 1.0 M M Ag+. = 0.34 V Cu2+ + 2e–  Cu E° = 0.80 V Ag+ + e– Ag  E°
A) increases. B) decreases. C) is unchanged. D) It is impossible to tell what will happen. 46. A concentration cell is constructed using two Ni electrodes with Ni2+ concentrations of 1.64 M and 2.85  10–4 M in the two half-cells. The reduction potential of Ni2+ is –0.23 V. Calculate the potential of the cell at 25°C. A) +0.341 V B) –0.222 V C) –0.256 V D) +0.111 V E) –0.0078 V 47. The standard potential for the reaction A(s) + B3+(aq) A3+(aq) + B(s) is 0.50 V. What is the equilibrium constant K for this reaction at 25°C? A) 3.1  1025 B) 3.2  10–26 C) 17 D) –17 E) 0.015 48. A concentration cell is constructed using two Co electrodes with Co2+ concentrations of 0.20 M and 4.4  10–5 M in the two half-cells. Determine the standard reduction potential of Co2+, given that the potential of the cell at 25°C is 0.108 V. A) 0 V B) +0.108 V C) –0.108 V D) +0.216 V E) This cannot be determined with the information given. Use the following to answer question 49: Consider the galvanic cell shown below (the contents of each half-cell are written beneath each compartment). The standard reduction potentials are as follows: Cr3+ + 3e–  Cr(s) E° = –0.73 V Br2(aq) + 2e–  2Br– E° = +1.09 V 49. What is the value of E for this cell at 25°C? A) 2.21 V B) 1.76 V C) 2.12 V D) 1.88 V E) 0.59 V Use the following to answer question 50: Consider an electrochemical cell with a copper electrode immersed in 1.0 M Cu2+ and a silver electrode immersed in 1.0 M Ag+. Cu2+ + 2e–  Cu E° = 0.34 V Ag+ + e–  Ag E° = 0.80 V
Ch%2011%20Practice.docx