Electrochemistry I

45 seconds

• Balance the redox reaction in ACIDIC media:

MnO4- + VO2+

Mn2+ + V(OH)4+

• MnO4- + 5VO2+ + 11H2OMn2+ + 5V(OH)4

+ + 2H+

45 seconds

• Balance the redox reaction in ACIDIC media:

Cr2O72- + U4+

Cr3+ + UO22+

• Cr2O72- + 3U4+ 2H+

2Cr3+ + 3UO22+ + H2O

45 seconds

• Calculate the electrode potential of a silver electrode immersed in a 0.0500 M solution of NaCl, given EAg+/Ag = 0.799 V , Ksp of AgCl = 1.82 x 10-10

• 0.299 V

30 seconds

Calculate the potential of a copper electrode immersed in 0.0440M Cu(NO3)2.

ECu2+/Cu = 0.337 V

• 0.297 V

40 seconds

• Calculate the potential of the zinc electrode immersed in 0.0100 M in NaOH and saturated Zn(OH)2.

EZn2+/Zn = -0.76

Ksp Zn(OH)2 = 3.0 x 10-16

45 seconds

• Calculate G of the process: Ag+ Ag(s) given

the Ksp of AgCl is 1.8 x 10-10 and the reduction potential of AgCl/Ag+ at 298 K is 0.222V

45 seconds

• Given the following data:

Fe3+ + Y4- FeY- (Kf = 1.3 x 1025 )

Fe2+ + Y4- FeY2- (Kf = 2.1 x 1014)

EFe3+/Fe2+ = 0.77 V

Calculate for the Eo of the process:

FeY- + e- FeY2-

• 0.13 V

Electrochemistry Conitnued…

July 12, 2011

30 seconds

• A 50.00mL aliquot of an unknown KMnO4 solution was added to 28.46mL of 0.1040 M Cr3+ solution to completely reduce Cr3+ to Cr. What is the normality of the permanganate solution?

0.03552N

• N = M*eq.

30 seconds

• A 24.76 mL H3PO4 is titrated with exactly 40.00 mL 0.1250 N NaOH. This requires an additional 10.10 mL of an H2SO4 solution with the same normality as the H3PO4 solution. What is the normality of the acids?

45 seconds

• A 0.2121 g sample of pure Na2C2O4 (134.00 g/mol) was titrated with 43.31 mL of KMnO4. Determine the (a) normality and (b) molarityof the KMnO4 solution.

30 seconds

• A current of 0.256 mA is passed through a solution of CuSO4 for 1 minute. How many grams of copper will be formed?

30 seconds

• How many seconds will it take to coat an iron rod with 0.2193 grams of zinc, if 0.500 mAcurrent is continuously supplied to a solution containing Zn2+ ions?

45 seconds

• If the standard potential of Cu2+/Cu and Cu+/Cu are 0.340V and 0.522V, determine the standard potential of Cu2+/Cu+.

• 0.158 V

45 seconds

• If the standard potential of Fe3+/Fe2+ and Fe2+/Fe are 0.77V and -0.44V, determine the standard potential of Fe3+/Fe.

• -0.04 V

Calculate the emf of a platinum electrode immersed in 0.0263 M K2PtCl4 and 0.1492 M KCl.

PtCl42- + 2e-

Pt(s) + 4Cl-, E = 0.73 V

• 0.78 V

120 seconds

• Find the emf of the cell:

Pt|U4+ (0.200M), UO22+ (0.0150 M), pH = 1.52 ||

Fe2+ (0.0100 M), Fe3+ (0.0250 M) | Pt

Fe3+ + e- Fe2+ E = 0.771 V

UO22+ + 4H+ + 2e-

U4+ + 2H2O E = 0.334V

120 seconds

• For the given cell, determine the emf:

Pt, H2| H+ (1.0 M) ||1M HOAc/ 1M OAc- buffer | H2 , Pt

Ka of acetic acid = 1.8 x 10-5