Penance Sp 2007

Let the blood bath begin...Point mongering at its finest!

2/28/2007
Note: These answers for the penance are not guaranteed, they are the result of students' efforts. If you are first
to contact the instructor with a right answer or find a mistake on this key, you will get extra credit for that
problem. First wrong answers do not count, only first right answers count toward the maximum 5 extra credit
points.  In any event, to get back all equilibrium points missed on Exam 1, you will need to complete all
penance problems correctly, make test corrections, and show the instructor that you understand equilibrium by
explaining 3 randomly chosen problems to the instructor. More answers will appear as more people do the
problems.
 Note: Bold answers are confirmed correct.

1    1.78 Heather Graehl     1.59 Harvinder Grewal  1.6  (2-sig. figs.) Michael Foulks 
2     8.58  Heather Graehl    8.6 (2-sig. figs.) Michael Foulks
3     .291  Heather Graehl   .293 Harvinder Grewal  .29 Lori Hartman
4     1.94  Heather Graehl   1.18 Harvinder Grewal  1.2 (2-sig. figs.) Michael Foulks
5     5.89  Heather Graehl   7.85 Harvinder Grewal  7.8 (2-sig. figs.) Michael Foulks
6     2.52  Heather Graehl    5.1 Oboli Gurara
7    13.5   Heather Graehl   13.2  Oboli Gurara
8      12.5  Heather Graehl   4.3  Oboli Gurara
9     .875  Heather Graehl  1.48  Oboli Gurara
10    12.7  Heather Graeh9.21 Oboli Gurara  9.2 Miguel Cobian
11   12  Heather Graehl
12    9.2  (2-sig. figs.) Michael Foulks
13    5.23  Heather Graehl  .523 Oboli Gurara
14    5.6 Oboli Gurara
15   [H+]=0.0847, [H2PO4-]=0.846, [HPO4-2]=7.31x10-5, [PO4-3]=5.54x10-9   Heather Graehl
      [H+]=0.0812, [H2PO4-]=0.0812, [HPO4-2]=6.30x10-8, [PO4-3]=3.26x10-19   Harvinder Grewal
     
[H+]=0.085, [H2PO4-]=0.085, [HPO4-2]=6.3x10-8, [PO4-3]=3.1x10-19 Oboli Gurara
      [H+]=0.081M, [H2PO4-]=0.081M, [HPO4-2]=6.3x10-8M, [PO4-3]=3.3x10-19 M  Michael Foulks
16  Molar solubility of AgCl = 1.3x10-5 M and molar solubility of Ag2CrO4 = 1.4x10-4 M. Michael Foulks Ag2CrO4 = 8.7x10-5 M Miguel Cobian    Heather Graehl [Ag2CrO4]=6.5x10-5 ,[AgCl ]= 1.33x10-5 M therefore Ag2CrO4 is more soluble. Eat dirt!
17   Ksp=  16.4  Keeley Mircetic
18   85 grams AgNO3 Miguel Cobian
19    pH = 5.4   Keeley Mircetic pH=3 Teresa Rapp
20    3x10-4M  Teresa Rapp
21   .10 moles  Teresa Rapp
22    11 moles NaCl Miguel Cobian
23    6x101 grams ZnCl2 Teresa Rapp  5x101 Harvinder Grewal
24   3.1 mole NH3  Teresa Rapp 
25   [Cl-]=.0058, [NH3]= 3.0, [Ag+]=1.1x10-10  Keeley Mircetic [Cl-]=.017, [Ag+]=1.2x10-10 Teresa Rapp [NH3]= 2.98,   Lori Hartman