1) Balance the following equation in an acidic solution: CH3OH(aq) + Ce4+(aq) °CO2(aq) + Ce3+ H2O + CH3OH + 6Ce4+°6Ce3++ 6H++ CO2 2) Balance the following equation in a basic solution: H2CO(aq) + Ag(NH3)2+(aq) °HCO3-(aq) + Ag(s) + NH3(aq) 5OH-+ H2CO + 4Ag(NH3)2+°4Ag + HCO3-+ 3H2O + 8NH3 3) Why is a salt bridge or porous disk necessary for the flow of electrons in a galvanic cell? A salt bridge or porous disk allows charge balance (it prevents charge build-up). 4) For the following unbalanced equation: Cu2+(aq) + Mg(s) ?Mg2++ Cu(s) Draw a spontaneous galvanic cell labeling the anode, cathode, electron flow direction, + and – signs, electrodes, and solutions. Assume the concentrations are 1M and T=298K. In addition, write the balanced equation, cell diagram, overall cell potential, equilibrium constant, ?G°, and specify how many electrons are transferred. Cu2++ Mg °Mg2++ Cu x° = +2.7 Mg¦ Mg2+¦Cu2+¦Cu (note I drew a porous disk, it could also be a salt bridge¦) ?G° = -nFx° = -521 kJ/mol Solve for K by lnK = (nFx°)/(RT) I don’t have a calculator with me, but everything is known except K. 2 electrons are transferred per mole as seen by n = 2 from the total reaction. Cu2+Mg2+CuMgAnode (-) e-e-Cathode(+)
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