Question

Please label as instructed, show all work and circle correct answers. Thanks

11. An electrochemical cell uses the following balanced chemical equation 3Ag (aq)+Al(s)AP(aq) + 3Ag(s) Ecell = +2.46 V A. (6 pts) Clearly label the following cell diagram with the following information: a. Anode and cathode b. Direction of electron flow under standard state conditions Direction of cation flow in the salt bridge c. AI Ag (s) (s) APtaa Aglaq) NO,(aq) NO (aq) B. (7 pts) What is the cell potential when [Ag"] is 1.00 x 10 M and the [AB] is 0.125 M? (6 pts) Predict whether the cell potential (Eceil) will increase, decrease, or remain the same when the following changes occur: C. Sodium chloride is added to the half-cell containing Ag'(aq), precipitating silver out as AgCl(s) a. b. Water is added to the half-cell containing Al3

Answer 1

e-flow AP Cation flow cation flow Anode: Oxidation: Al -------> Al3+ + 3e- Cathode: reduction: 3Ag+ + 3e-------> 3 Ag A) a: anode is Al electrode and cathode is Ag electrode. b: electron flow from anode to cathode means Alto Ag. c: cation flow from Al to the solution and solution to Ag electrode. B) Cell: Al(s)[A13+(aq, 0.125M)|Ag+(aq, 1.00*10^-6M) Ag(s) Electrode potential can be calculated by Nernst equation: Ecell = Eºcell - (RT/F)*In([A13+]/[Ag+^3)...assuming T=298K = +2.46 - ((8.314*298)/(3*96500))*In((0.125/(1.00*10^-6))) = +2.36 V

c) a) by adding NaCl we are decreasing the concentration of Ag+ beacuse it precipitates our the Ag+ ion and hence there will be less Ag+ ion concentration. This leads to decrease in the "In" term in the equation and hence cell potential also decreases. b) By adding water to the half-cell, we are making more dilute solution of A13+ ions and hence it is decreasing the concentration of Al3+ ions. This increases the "In" term and hence overall cell potential also increases.