Ch 17 QUIZ - AP Chemistry

chathamschools.org

Ch 17 QUIZ - AP Chemistry

Name:_______________________________ Date:_________________ Hr:____AP CHEMISTRYCh 17 – ElectrochemistryFree Response (37 points)Show all work with appropriate significant figures for full credit.QUIZ3.(3 points) Which one of the following is least likely to be a product of a redox reactionbetween sulfuric acid and zinc metal? Justify your response.H 2 H 2 S SO 2 SO 34.(3 points) Consider the following half-cells which are set up under standard conditions.Half-Cell Electrode ElectrolyteI Metal A A 2+ (aq)II Platinum B 2+ (aq) & B 3+ (aq)III Metal C C + (aq)When a galvanic cell is constructed from half-cell (I) and half-cell (II), the electrode in half-cell(II) is the cathode. When a galvanic cell is constructed from half-cell (II) and half-cell (III), theelectrode in half-cell (III) is the cathode. Which of the following is the strongest oxidizingagent? Justify your response.A 2+ (aq) B 2+ (aq) B 3+ (aq) C + (aq)2012Page 2 of 6


Name:_______________________________ Date:_________________ Hr:____AP CHEMISTRYCh 17 – ElectrochemistryQUIZ5.(8 points) The overall reaction in the lead storage battery, with sulfuric acid as theelectrolyte, isPb(s) + PbO 2 (s) + 2 H + (aq) + 2 HSO 4 - (aq) 2 PbSO 4 (s) + 2 H 2 O(l)(a) For the cell reaction given, ∆H° = -315.9 kJ and ∆S° = 263.5 J/K. Calculate E° and K.(b) Calculate E at 25°C when [HSO 4 - ] = [H + ] = 4.5 M.(c) Calculate E at -10.0°F (-23.3°C) when [HSO 4 - ] = [H + ] = 4.5 M.2012Page 3 of 6


Name:_______________________________ Date:_________________ Hr:____AP CHEMISTRYCh 17 – ElectrochemistryQUIZ6.(8 points) A zinc-copper battery is constructed as follows at 25°C:Zn | Zn 2+ (0.10 M) ║ Cu 2+ (2.5 M) | CuThe mass of each electrode is 200. g and each half-cell contains 1.00 L of electrolyte solution.(a) Calculate the cell potential when this battery is first connected.(b) Calculate the mass of each electrode after 10.0 A of current has flowed for 10.0 hours.(c) Calculate the cell potential after 10.0 A of current has flowed for 10.0 hours.2012Page 4 of 6


Name:_______________________________ Date:_________________ Hr:____AP CHEMISTRYCh 17 – ElectrochemistryQUIZ7.(10 points) Consider the standard galvanic cell based on the following half reactions:Cu 2+ + 2 e - Cu and Ag + + e - AgThe electrodes in this cell are Ag(s) and Cu(s). Does the cell potential increase, decrease, orremain the same when the following changes occur to the standard cell? Justify your response(or you will receive zero credit).(a) CuSO 4 (s) is added to the copper half-cell compartment (assume no volume change).(b) NH 3 (aq) is added to the copper half-cell compartment. Hint: Cu 2+ reacts with NH 3 toform Cu(NH 3 ) 4 2+ (aq).(c) NaCl(s) is added to the silver half-cell compartment.(d) Water is added to both half-cell compartments until the volume of solution is doubled.(e) The Ag(s) electrode is replaced with a Pt(s) electrode.2012Page 5 of 6


Name:_______________________________ Date:_________________ Hr:____AP CHEMISTRYCh 17 – Electrochemistry8.(5 points) A voltaic (galvanic) cell is based on the following half-reactions:Fe 2+ + 2 e - Fe(s) E° = -0.440 V2 H + + 2 e - H 2 (g) E° = 0.000 Vwhere the iron compartment contains an iron electrode and [Fe 2+ ] = 1.00 x 10 -3 M and thehydrogen compartment contains a platinum electrode, P H2 = 1.00 atm, and a weak acid, HA, atan initial concentration of 1.00 M. If the observed cell potential is 0.33 V at 25°C, calculate theK a value for the weak acid HA.QUIZI affirm that the work shown on this quiz is entirely my own effort and that no resources other than those specifiedwere used.____________________________________Student Signature2012Page 6 of 6

More magazines by this user
Similar magazines