Half-ReactionE°(volts)Cd(OH)2(s) + 2 e¯ ---> Cd(s) + 2 OH¯(aq)- 0.809NiOOH(s) + H2O(l) + e¯ ---> Ni(OH)2(s) + OH¯(aq)+ 0.490a) Write a balanced equation for the process that produces electricity ina nicad battery and specify the half-reaction that occurs at the anode.b) Calculate the potential expected for a nicad battery.c) If such a battery produces a current of 50 milliamps for a period of 6.00 hours, how many electrons will be transfered?d) What mass of cadmium will undergo oxidation (or reduction) during the process in part (c)?5. (14%) Write net equations for each of these reactions. Use appropriate ionic and molecular formulas for the reactions andproducts and omit formulas for all ions or moleculs that do nottake part in a reaction. Write structural formulas for all organicsubstances. You need not balance the equations. All reactions occur in aqueous solution unless otherwise indicated.
a) A piece of calcium is added to water.b) Concentrated hydrochloric acid is added to manganese(IV) oxide.c) Solutions of lead acetate and dilute sulfuric acid are mixed.d) Sodium cyanide is added to water.e) Silver is added to dilute nitric acid.f) Excess aqueous sodium hydroide is added to aqueous aluminum nitrate.g) A mixture of acetic acid and excess methanol is refluxed in the presence of a catalyst.6. (11%) Sulfur can form many different compounds, including H2S, SCl2, SCl4, SF2, SF4, and SF6.a) Account for each of these observations.i. There are no known compounds of sulfur in an odd atomic ratio with another element, such as SF3.ii. The highest known hydride of sulfur contains just two hydrogen atoms per sulfur.iii. Fluorine combines with sulfur to form SF2, SF4, and SF6; chlorine combines with sulfur to form SCl2and SCl4but not SCl6.b) Write an electron dot structure for SF4.c) Sketch the structure of SF4, give the F-S-F bond angles and identify the hybrid orbitals used by sulfur in this compound.7. (14%) The conductivity of several aqueous solutions was tested, giving these results.SolutionRelative Conductivity0.10 M CuCl2(aq)high0.10 M Cu(CH3CO2)2(aq)high0.10 M H2S(aq)lowa) Account for the conductivity results reported for 0.10 M aqueous solutions of CuCl2, Cu(CH3CO2)2, and H2S.Two additional tests are to be performed, this time on mixturesof solutions.SolutionRelative Conductivity0.10 M CuCl2(aq) + 0.10 M H2S(aq)?0.10 M Cu(CH3CO2)2(aq) + 0.10 M H2S(aq)?b) For each of these reaction mixtures, answer these questions.i. Write a net ionic equation, giving state symbols for all species.ii. Describe any visual changes expected in mixing these solutions.iii. Predict the relative conductivity expected for the final solution that results from the mixture of the two solutions. Explain your answer.8. (12%) Account for each of these observations about the rates of chemical reactions and the factors that affect them.
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