Monthly Archives: September 2009

9. Monday, September 28, 2009

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Aqueous reactions, Electrolytes, Solubility and Precipitation
1. Read Chapter 3 (122-131)
2. 3.5, 3.6, 3.7, 3.8, 3.10 OWLs due Thursday Oct. 1

Exam 1 is coming soon – more info on the “Exam” page

Sept 28

Sept 28

Lecture was a bit flat today – and then my computer freaked out, just to put icing on that cake.  But the class is pretty sharp, so hopefully you got the point that reactions in water include both precipitation reactions, and acid-base reactions..  I fixed the lecture recording so that all material is present.

Chapter 3 Book HW

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Chapter 3:   # 70, 71, 76

Not collected, but these are great problems to challenge yourself. Really good subjects for study groups. Answers are written in the form of a comment (below) – no peeking!

Fully worked-out answers can be obtained upon email request to any of the study group coordinators, or me, or Nag. But we’ll only send you one answer. To get more than one answer, you’ll need to find other students (hopefully with different answers!) or a study group.

7. Wednesday, September 23, 2009

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Mole/mass conversions, Percent composition
1.  Read chapter 2 (82-94)
2 . 2.7, 2.9, 2.10, 3.1, 3.2 OWLs due Thursday, September 24

Sept 23 Lecture

Sept 23 Lecture

NOTE: Table of ions that you need to know is on page 74, Table 2.4.  I showed the table from the older edition of the textbook during lecture


Some interesting comments near the end of lecture regarding the distinction between a physical change and a chemical change.  Although it is correct that moderate inputs of energy often lead to physical changes, the most important criterion is that of bonding.  If the bonding between atoms changes, then it is a chemical change – so heating Co(H2O)6Cl2 to produce CoCl2 absolutely changes the bonding within this chemical compound.