[YWANKER]

Hi, I realize that this is my first post and I put up 5 questions, but this is part of a homework set of 30+ questions and these were the ones that I did not understand no matter how long I worked at them.  I read the forum rules, so I tried to make the post in accordance to the rules.  Thanks.

1. A galvanic cell is constructed with a silver-silver chloride electrode, and a nickel strip immersed in a beaker containing 8.18x 10-2 M solution of NiCl2. Determine the balanced cell reaction and calculate the potential of the cell. Enter in volts. (assume a temperature of 25oC)

2. Consider an electrochemical cell consisting of two vessels connected by a porous separator. One vessel contains 0.700 M HCl solution and an Ag wire electrode coated with AgCl solid. The other vessel contains 1.50 M MgCl2 solution and a Mg wire electrode. First determine the net reaction, and then calculate the emf of this cell. Enter your answer in volts.

3. Electrochemical cells can be used to measure ionic concentrations. A cell is set up with a pair of Zn electrodes, each immersed in ZnSO4 solution. One solution is created to be exactly 0.400M, and the potential on its electrode is measured to be 0.050V higher than the other electrode. What is the concentration of the other solution? Enter your answer in M.

4. A galvanic cell is constructed with a silver-silver chloride electrode, and a nickel strip immersed in a beaker containing 8.18x 10-2 M solution of NiCl2. Determine the balanced cell reaction and calculate the potential of the cell. Enter in volts. (assume a temperature of 25oC)

5. *For this last question, I got the first three parts of the question but was unable to do the last part.
In the upper atmosphere, ozone is produced from oxygen gas in the following reaction. Calculate ΔHo for this reaction.
3 O2(g) --> 2 O3(g)

Enter your answer in kJ and give 3 significant figures.
285
   
Calculate ΔSo for ozone formation. (Enter your answer in J/K and give 3 significant figures).
-141
   

Calculate ΔGo for ozone formation. (Enter your answer in kJ and give 3 significant figures).
326
   

Assume an atmosphere where p(O2) = 0.060 atm, and where T = 298 K. Below what pressure of O3 will ozone production be spontaneous? (Enter your answer in atm).  This is the part I did not get.