Grades (and the overall average) for the weekly hand-in problems are here.  If you think any grade is missing or recorded incorrectly, please come to my office with the graded problem as soon as possible, but before the exam in any event.  "ex" indicates an excused missing set: this does not factor into the average.  If a grade is missing without an excuse, it counts as zero.

Special office hours: Tuesday 12/9 through Wednesday 12/17: 2 to 4 PM daily.

Study Guide for Exam 3.  Near the bottom of the page, delete "elementary basic features of ligands binding to metals or metal ions."  Also, delete item 1.f.iii: effect of temperature on equilibria.  This is an application of LeChatelier's principle that I have not yet discussed at any length.

Correction to handout on pH of Salts: (corrected version on-line)

    The approximate pH of a solution of a salt containing an ampholyte anion is  ½(pK₁ + pK₂ ),
where K₁ and K₂ are the successive acidity constants of the acid conjugate to the ampholyte.

Because there was no hand-in problem due Oct. 23, there is no longer a simple correspondence between the numbering of practice and hand-in problems:
Hand-in problem #7 relates to practice problem sets 7 and 8 (solubility and buffers)
Hand in problem #8 relates to practice problem set 9 (titrations)
Hand in problem #9 relates to practice problem sets 9 and 10 (combining K's and redox)
Hand in problem #10 relates to practice problem set 11 (electrochemical cells)
Hand in problem #11 relates to practice problem set 12 (thermodynamics)

Hand-in problem 7D.  Acetic acid/acetate is also an acceptable answer; the solution set says formic acid/formate.  If you made your buffer with acetic acid, bring it to me so you can get the credit you deserve.

References for Binary Liquids: P-X and T-X Diagrams.  I have been asked for suggested readings about these.  Many general chemistry texts cover this well, for example, Segal (2/E), section 6.8; Oxtoby, Freeman and Black (4/E) section 6.7; and Atkins and Jones (4/E) sections 8.18-8.20.  See the course syllabus for full text information.  If consulting a different text or edition (/E), look in the index for "binary liquids".

Corrections: there is a new web page where I post corrections to any errors found in the problem sets (practice or hand-in).  I very much appreciate you telling me if you find an error so it can be corrected for all.

[Chapter 7].  I was asked why Chapter 7 is in brackets in the readings in the syllabus.  The reason is that we are not covering atomic structure in any depth in this course.  Most of you did this very thoroughly in high school.  As with other topics, the lectures, handouts, problems, and lab exercises should be your guide in what to emphasize in your study.

Chemistry Help.  The Dean of Studies Office has arranged student tutors for this course.  They are available in 804 Altschul on Tuesday and Wednesday evenings, between 6:30 and 9:30 PM. These tutors, who took the course last year, will not do your problems or check your work, but they are there to answer your questions about lectures, readings, problems, etc.  Just drop in.

Inorganic Nomenclature.  On 9/4, I was asked about the order for writing elements in molecular formulas, and I said I was not sure of the exact rule.  I have since consulted IUPAC's Principles of Chemical Nomenclature.  The rule is generally based on electronegativity: the more electonegative element is written later.  However there are different ways to define electronegativity, with slightly different results, so IUPAC, which determines such rules, established the sequence shown in the table below.  With the exception of H, the rule is simple: for all but Lanthanides, elements in a higher group (column) go after those in a lower; within a group, those above go after those below.  H is special: in molecular substances it goes between Group 15 and Group 16.  Examples: SO₂, H₂S, NH₃, IBr... 
Do I expect you to know and use this rule?  No.  You will become familiar with many compounds like those above, but if you wrote HClO₂ or ClO₂H instead of HO₂Cl I would give you full credit, since the essential information --- what atoms and how many of each are in the molecule --- is the same.  Indeed, we will often write this molecule as HClO₂, since that conveys some structural information.

What is our policy with respect to calculators? Is there a restriction on the type you may use? No: you may use any kind. If, however, you have a calculator into which equations can be programmed, you must empty the memory of all equations before coming to an exam. Failure to do so is an honor code violation, and there may be spot checks. Note that you do NOT need a fancy calculator: any one that can evaluate logs and exponents is sufficient. The most important thing for exams is that you are fully familiar with the calculator you are using!

Many class handouts are posted on the web.  However the weekly hand-in problem is not: it is distributed in class only.  If you miss class, you must come to my office to get your copy.  Originals only (no photocopies) are accepted: this way we have equal numbers of each version. All answers must be written on the original sheet, not on an added page.  Please work out the problem on scratch paper; copy it to the problem sheet after you have found the answer. These policies are designed to make the grading prompt, accurate, and fair.