Converting Densities

I'm looking over the summer work submissions, and it appears the one giving people the most trouble is #24, converting densities.  They are tricky, mainly because you often have to deal with cubed units (for volume).  A good working of a problem like the ones you see online is here.  Just remember that you have to multiply a cubed unit by a conversion factor three times (or cube the factor) in order to cancel it.

Comments?  Other questions?

Happy Birthday, Avogadro!

Holy Mole-y! Today is Amadeo Avogadro's birthday - 234 years young!  I'd recommend celebrating with a toast of a mole of water (only 18 mL) rather than blowing out 234 candles.  You can also see more about Mr. Avogadro at http://chemistry.about.com/b/2010/08/09/this-day-in-science-history-august-9-amedeo-avogadro.htm

To Err Is... Smart!

There's an interesting (and long) article at http://www.boston.com/bostonglobe/ideas/articles/2010/06/13/the_bright_side_of_wrong/about how inductive reasoning - seeing patterns, putting things together - both makes humans smart and makes us prone to errors. A good concept to have in mind thinking about a challenging Junior or Senior year making sense of chemistry and other good stuff. A quote for you from the 4-page article:

As ashamed as we may feel of our mistakes, they are not a byproduct of all that's worst about being human. On the contrary: They're a byproduct of all that's best about us. We don't get things wrong because we are uninformed and lazy and stupid and evil. We get things wrong because we get things right. The more scientists understand about cognitive functioning, the more it becomes clear that our capacity to err is utterly inextricable from what makes the human brain so swift, adaptable, and intelligent.

IB Chemistry Summer Assignment Clarification

The assignments posted for last years' AP Chemistry class are essentially the same as yours for IB next year.  I had only briefly looked at the summer assignments page a couple weeks ago and thought it had been updated, but not it's just not so.  Scroll down to find the most updated information on your assignment, including a google docs link to printable versions of everything.  Please send me an email soon, so you can be an author of this blog and post questions or interesting stuff (related to Chemistry, please).  I'll occasionally post stuff that I come across and announcements here, too.  I'm looking forward to the emails rolling in!

We don't know everything yet...

Interesting article about determining the correct structure of a molecule invovled in tuberculosis infection: http://www.rsc.org/Publishing/ChemScience/Volume/2010/07/edaxadiene.asp
It seems so obvious when you see the structure drawn out, but how you get an organic molecule's structure is one of the things we'll look at next year.

Google Docs - assignment sheet and "Suff I Should Know"!

Click to see the assignment and the Stuff you should know, formatted nicely and printable:
https://docs.google.com/fileview?id=0B-Q4wLLg8b1JOWViMTFjMTUtMjc1ZC00ZjI5LWFkODMtZDgxYjg0OThiMjhm&hl=en

Welcome to your second year of Chemistry!

I'm looking forward to the summer as much as the next guy, but I also want us to be ready for next school year. I've pasted below the assignment you need to complete this summer. Please note the due date is a week before classes start!

I am excited to work and learn with you during the 2010-11 school year. As student and teacher, we are part of a team with one primary goal: to prepare you for AP Chemistry exam to be given in May of 2011. To get us started toward this goal, I am assigning some problems to be worked over the summer to keep your first year of chemistry “fresh” and to reinforce key topics.

1. Email Mr. Soderholm at Scott_E_Soderholm@mcpsmd.org. Please tell me you are in AP, and what chemistry class you have taken already. I will add you to the authors list for our class blog (see resources below for details).


2. Visit http://chemistry2.csudh.edu/homeworkn7/hwintrocsn7.html and answer the review questions I have assigned below. Continue answering questions until you have five (5) questions answered correctly. If you do not have access to a computer at home, please go to the nearest library and access it from there. These problems are due by August 23 (a week BEFORE classes begin). This assignment will be assessed as your first quiz (formative assessement).


3. On the back of this paper (or the file stuffIshouldKnow.pdf) are some facts that you will be expected to memorize this year. Make a set of flash cards of at least the ions list and solubility rules to be scored as your first practice homework assignment. I strongly recommend you start using your cards now, since the material will be used during our first units.
   

   o Basic Concepts #0 (Significant Figures) NOTE: Use the online textbook to help with this. o Basic Concepts #2 (Direct and Inverse Relationships) o Basic Concepts #4 (Scientific Notation) o Basic Concepts #5 (Smaller, Larger, or the Same?) o Basic Concepts #6 (Percentage) o Basic Concepts #9 (Mass, density and volume) NOTE: The program will only accept answers in 2 significant figures. o Conversions #24 (Converting Densities) o Conversions #25 (Converting Temperatures) o Atoms and Elements #31 (Elements, moles and mass) o Gases #44 (Ideal Gas Law) o Solutions #53 (Molarity, mass and volume) o To submit your scores: Type your name followed by a comma and "AP or IB as appropriate" (ex: “Bob Vila, AP”). Select "Soderholm, S" from the instructors list and hit “Submit Homework!” o Again, please contact me or your peers if you have trouble with these assignments.

Resources:

• This blog. Don’t forget to email me to get full access please!


• http://preparatorychemistry.com/ (a free online general chemistry text, with tutorials)


• Your 1^st year Chemistry notes


• Your peers: Email, telephone, in person, our class blog, etc.


• Mr. Soderholm’s email: Scott_E_Soderholm@mcpsmd.org