Electrochemistry
1.Consider the Daniel Cell at the indicated molalities:
Zn(s)|ZnSO4(aq, 0.100 M)||CuSO4(aq, 0.500 M)|Cu(s)
a) Calculate the ionic strength I and mean activity coefficient (gamma+-) for each species, the latter using the Debye - Hückel limiting law, and compare this value to those found in
the data tables (i.e., (gamma +-),ZnSO4 = 0.150 at 0.100 M; (gamma +-),CuSO4 = 0.0620 at 0.500 M).
b) Calculate E using the molalities indicated in the above Cell and the mean activity coefficients from the data tables. What is the relative error if only the concentrations are used?
(You can skip no. 1 as I got the answer for it, elsewhere.)
2. The Edison storage cell is described by,
Fe(s)|FeO(s)|KOH(aq,
a)|Ni2O3(s)|NiO(s)|Ni(s)
The half-cell reactions are as follows,
Ni2O3(s) +H2O(l) + 2e– ---->
2NiO(s) + 2OH–(aq. ) Eo = 0.40 V
FeO(s) + H2=2O(l) + 2e– -----> Fe(s) + 2OH–(aq) Eo = –0.87 V
a) What is the overall cell reaction?
b) How does the cell potential depend on the activity of KOH?
c)How much work can be obtained per pound (453.6 g) of the active materials in the cell?
3) Graph the radius of the ionic cloud as a function of ionic strength of a sodium ion dissolved in ethanol at 298.15 K for a concentration of NaCl from 0.001 to 0.010 M at 0.0001 intervals in ethanol; for ethanol, epsilon r = 25.3 and rho s = 789 kg m-3. Note: remember to include a sample calculation for both I and k-1 as well as a copy of the spreadsheet and final graph.
Kinetics
4. The gas phase reaction 2 N2O5(g) ⟶ 4 NO2(g) + O2(g) obeys first order kinetics. The half- life for the reaction is 8.95×104 s at 0.0 oC and the half-life for the reaction is 795 s at 50.0 oC.
a) Evaluate the Arrhenius parameters Ea and A.
b) Calculate the rate constant at 25.0 oC.
5) Bananas are somewhat radioactive due to the presence of substantial amounts of potassium. The isotope of potassium is radioactive and decays by the two different pathways shown below:
4019K --(k1)--> 4020 Ca +beta- (an antineutrino) (89.3%)
4019K ⎯⎯(k2)--> 4018 Ar +gamma+ beta (a gamma ray and a neutrino) (10.7%)
The half-life for potassium decay is 1.251×109 years. Evaluate the rate constants k1 and k2.
Electrochemistry 1.Consider the Daniel Cell at the indicated molalities: Zn(s)|ZnSO4(aq, 0.100 M)||CuSO4(aq, 0.500 M)|Cu(s) a) Calculate...
Introduction The chemical reactions involved in this experiment are: CuSO4(aq) + Zn(s) → ZnSO4(aq) + Cu(s) Zn(s) + H2SO4(aq) → ZnSO4(aq) + H2(g) The copper on the surface quickly reacts with oxygen according to the following reaction: 2Cu(s) + O2(g) → 2CuO(s) Experimental Procedure Dissolve completely about 0.5 to 0.7 g of copper (II) sulphate pentahydrate in about 10 to 20 mL of deionized water. Calculate the amount of zinc powder that must be added to a copper sulfate solution...
Given the following electrolytic cell: The current is discharged into the electrolytic cell containing the solution CuSO4(aq) 1.0M at 25 oC. During the operation of the cell, copper Cu(s) is deposited on one electrode and oxygen O2(g) gas is released, near the second electrode. O2(g) + 4H3O+(aq) + 4e- 6H2O(l) Eo= 1.23V Cu2+(aq) + 2e- Cu(s) Eo= 0.34V A. Write the direction of the flow of electrons in the cell. B. Write the electrolysis equation that occurs in the cell....
Candidate l: Zn(s) | Zn2+(aq,0.500 M) I Cu2+(aq, 1.00 M) Cu(s) Candidate 2: Pb(s) | Pb2+(aq, 0.500 M) || Cu2+(aq, 1.00 M) Cu(s) Candidate 3: Mg(s) | Mg2+(aq, 0.500 M) | Pb2+(aq, 1.00 M)| Pb(s) (a) 6 pts) Choose one of the candidate voltaic cells #1, #2, or #3. Draw a schematic cell diagram for the candidate voltaic cell of choice. Clearly label anode, cathode, electrodes, ions and their concentrations, salt bridge, and the flow of electrons. (b) (5 pts)...
Consider the voltaic cell and reduction half potentials: Zn(s) | Zn 2+(aq) (0.100 M) || Ni2+(aq) (1.50 M) | Ni(s) Zn 2+ (aq)/Zn (s) E o = - 0.760 V Ni2+ (aq)/Ni (s) E o = - 0.230 V a) Sketch the voltaic cell represented with the above line notation. Label the anode and cathode and indicate the half-reactions occurring at each electrode and the species present in each solution. Also indicate the direction of electron flow (3 marks). b)...
salt bridge Zn(s) electrode Culs) electrode 1.0M Zn (a 1.0 M Cu (aq A voltaic cell similar to that shown in the figure above is constructed. The electronic device shown at the top of the figure is a volt meter. One electrode compartment consists of a zinc strip placed in a 1.0 M ZnCl2 solution, and the other has a copper strip placed in a 1.0 M CuSOA solution. The overall cell reaction is: Zn(s)Cu2+(aq)= zn2+ (aq ) Cu (s)...
Calculate the standard cell potential (∆Eo) for the galvanic cell: Ni (s) 1 Ni2+ (aq) II Ag+ (aq) 1 Ag (5) Given: E Half Reaction Ag+ (aq) +e- → Ag (s) Ni2+ (aq) + 2e- → Ni (s) 0.79 Volts -0.23 Volts
*redox reactions in electeochemical cells* c) Fe/0.1 M FeSO4//0.1 M CuSO4/Cu I soaked a porous cup in tap water for a few minutes and then i let it stand in a 100 ml beaker containing 10ml of 0.1 M FeSO4. I added enough 0.1M CuSO4 to the cup until the two liquid levels were the same height. I inserted a zinc strip into the 0.1 M FeSO4 and a shiny copper strip into the 0.1 M CuSO4. I connected the...
And a copper electrode with 0.500 M Cu?' as the second half cell Cu2+ (aq) + 2 e Cu(s) Eºred= 0.337 V The measured cell potential when the water sample was placed into the silver side of the cell was 0.0905 V. Write the balanced equation for the overall reaction in acidic solution. AgCl(s) + Cu2+ (aq) + 3 e → Ag(s) + Cu(s) + CI+ (aq) 04- 03. 02. + 2 O 4+ 1 2 3 4 5 6...
Consider the following electrochemical cell at 298.15 K: Cd(s) | Cd(NO3)2 (aq, m = 0.200) || KCl (aq, m = 0.0150) | Ag(s) | AgCl(s) A) Write the overall reaction. B) Calculate the standard cell potential and ∆GR°. C) Calculate the cell potential and ∆GR assuming activity coefficients are 1.00. D) Calculate the cell potential and ∆GR using the Debye-Huckel limiting law for the mean ionic activity coefficients. E) Is the cell reaction spontaneous as written? F) How much electrochemical...
NAME: General Chemistry II Electrochemistry Quiz 1) Consider the cell described by: Cu Cu2+ (1.00 M) || Zn2+(1.00M) | Zn a) Draw this cell, labeling everything including the cathode, anode and salt bridge and any ions in solution. Show the flow of electrons in the circuit. b) Write out the reduction and oxidation half reactions for this cell. OVER → 2) Balance the following redox equations using the half-reaction method. Show all steps. a) ClO3 + + CH-1 → Cl2...