Author Archives: Charles Taylor

CHM 110: Some “final” announcements

CHM 110 students

Just a few quick announcements before tomorrow’s final exam:

  1. Check [Desire2Learn] on Saturday for your grades.  I will also post a note on the main course web site (here) when I have finished calculating your grades.
  2. You do not get to keep a copy of your final exam.  However, if you would like to view your graded exam, then visit me during office hours sometime next week.
  3. If you’re registered for CHM 111, class begins on Monday morning.  The required books and accessories for CHM 111 are the same as for CHM 110.  Class meeting times and locations are the same as for CHM 110.  If you’re signed up for a different section of CHM 111 (i.e. you’re signed up for section 2 in 110 but section 1 in 111), your lab times might be different.  Check your schedule!
  4. If you’re finishing CHM 110, have decided you would like to take CHM 110, and are not registered for the course – you may still register for CHM 111 as late as Monday.  Come to Monday’s class and ask me for a registration form right after the class is over.
  5. Please remember to bring both a calculator with good batteries and something to write with to the exam!

Any last-minute questions?  Ask them here!  I will be checking periodically for questions until 11:00 PM tonight.

CHM 110: Grades updated

CHM 110- students:

If you’re in section 1, you may view your lab average (and your updated course average) on [Desire2Learn].  If you are in section 2, I will post your lab averages as soon as I receive them  from Mr. Sneeringer.

Also, remember that CHM 110 lecture will not meet on Thursday morning (lab is unaffected).  If you have any questions about the final, please drop by the office or leave a comment on this post.

(If there are any CHM 100 students reading this post, CHM 100 lecture meets as usual on Thursday!)

Remember to bring a calculator with good batteries to the final on Friday!

CHM 110: Some example molecules from 6/16/10

Here’s formaldehyde.  You can see the trigonal planar structure clearly.  In some of these images, electrostatic potential is indicated with blue (for negative) and red (for positive) to show the polarity of these molecules.  Formaldehyde is a polar molecule.

Formaldehyde - with ESP shading

Take a look at the pyramidal shape of ammonia.  Its nitrogen atom is the top of the pyramid, while its hydrogen atoms form the base.  Ammonia is a polar molecule.

Ammonia - with ESP shading

Ammonia - with ESP shading

Water is a bent molecule, which gives the molecule a hydrogen “side” and an oxygen “side”.  This makes the molecule polar.

Water - with ESP shading

Water - with ESP shading

Difluoromethane is a molecule that, at first glance, may appear nonpolar.  It has two hydrogen atoms and two fluorine atoms, but their tetrahedral arrangement around the central carbon atom makes the molecule have a hydrogen “side” and and fluorine “side”.

Difluoromethane

Difluoromethane

Since fluorine atoms are very electronegative, their arrangement makes difluoromethane a polar molecule.

Difluoromethane - with ESP shading

Difluoromethane - with ESP shading