CHEMISTRY 31

Fall, 2014 - Dixon

Homework Set 2

 

Chapter                                       Problems                                             Date to finish    

Set 2.1                                                                                                          Oct. 22

Ch. 6                                              15-17, 19, 21, 23, 25, 33, 36, 43, 48

Ch. 7                                              1, 3, 4a,b, 9, 12, 19, 21, 23 [postponed until set 2.2]

text problem solutions             

 

Additional Problem 2.1. 

SrCO3 is a sparingly soluble salt.  Using the Ksp from the appendix,

a) Determine the concentrations Sr2+ and CO32- when SrCO3 is dissolved in pure water ignoring secondary reactions of Sr2+ and CO32- and ignoring the activity from dissolved Sr2+ and CO32-.

b) Using the concentrations of  Sr2+ and CO32- found in a), determine the ionic strength of the solution, the activity coefficients of Sr2+ and CO32-, and account for these in a recalculated concentration of  Sr2+ and CO32- (only one iteration of this calculated is expected).  Continue to ignore reactions of Sr2+ and CO32-.  (5 pts)

solutions

 

Set 2.2                                                                                                          Nov. 5

Ch. 7                                              27, 28a, b

Ch. 8                                              3

Ch. 17                                            1, 3, 4, 11, 16

Additional Problem 2.2

Using the systematic method and information in the Appendices F and J (note that log value is given in Appendix J), determine [SCN-], [Hg2+], and [HgSCN+] at equilibrium when Hg(SCN)2(s) is dissolved in water.  Be sure to show all steps using the systematic method.  Neglect activity and assume that neither Hg2+ nor SCN- react significantly with water (no formation of HgOH+ or HSCN).  Hint: you will probably want to make an assumption in the charge balance to simplify the problem and then test to see if the assumption is valid.

 

Set 2.3                                                                                                          Nov. 10

Ch. 22                                             7a, 17, 19, 22, 28a-f, 30, 38

No Additional Problem