End of the year info May 14, 2008

Seniors, if you would like to to know your exemption status, the names of those exempt according to grades earned in my class has been submitted to the office for an attendance check.  If you just can’t wait to find out from them, send email to bergerj@delphi.k12.in.us with the subject line “AM I EXEMPT?” and I will let you know.  That way, if you have any questions about your status, we can deal with them in a timely manner.  I realize some of you have some work you are doing with Mr. Thompson, and this will be included in your final grade, but is not eligible for exemption status as of now because those names had to be turned in today.  You will get credit for the work you have done.  If you are not exempt, material from second semester is fair game for your finals and review sheets will be posted here soon for each class.

AP Chem - Lab due Monday - Kinetics April 27, 2008

So Torie commented on another post but I thought this deserved its own post.  Here is what she said:

I am confused on the lab with the Mg and HCl.
I got all of the calculations except for the ln [H3O]+. I dont know how to figure that out…

and then the part after that… ln rate= m ln[H3O+] + ln k

I am not sure what to do with that…

[H3O+] is the concentration of H+ or H3O+(same as H+ except it has water attached) in solution.  Since HCl is a monoprotic strong acid, when placed in water, HCl ionizes into H+ and Cl-.  If you have 0.25M HCl, the concentration of H+ in solution will be 0.25M because there is a one to one mole ratio.  So, when they ask for ln[H+], just calculate the natural log of the concentration of your acid.  Since slope-intercept form is y=mx+b, if you plot natural log of rate on the y axis and ln of concentration on the x axis, your y intercept will be the natural log of the rate constant.  This is useful if you want to find out what your rate constant is.  YOu can get the point-slope equation by adding a trendline to your data in Excel and in the extra options, show the equation.  See me in the morning if you still have a question.

Chemical Nomenclature Practice February 18, 2008

Use the following websites to “train” for Friday’s Quest. 

http://library.thinkquest.org/10429/high/nomen/nomen.htm - review with quiz at end

http://chemistrygeek.com/rainbow/launch.htm - Writing and Naming Compounds 

Intermolecular Forces January 28, 2008

Helpful websites:

Tutorial from AUS-e-TUTE

ChemED from Purdue

Georgia Southern’s website with pictures from class and other tutorials for VSEPR and polarity (good for quest review)

AP Chem Chapter 5 Test - Gas Laws January 17, 2008

Basically, you want to know how the properties of gases affect each other, what makes gases special from other phases of matter, the differences of the ideal gases and real gases, how to use ALL your equations and what the variables stand for (the appropriate R values for each), how to convert from one unit to another, whenever you used temp. it should be in Kelvins, gas law stoichiometry, mole fraction and partial pressures, the postulates of the KMT, diffusion and effusion.  You will be given equations and constants.

Significant Digits Reminder January 10, 2008

Remember that significant digits are important because they help to reflect the precision of the instruments used to make the measurements involved in a calculation.  I have posted about this before with some websites you can use to help you practice.  The second website is actually quite good and has a lot of practice for you to try.  The third website, I think, has been removed but the other two are fine.  If you have any questions after doing these tutorials, please feel free to comment, even if you are not one of my students!

AP Chemistry Chapter 5 help January 1, 2008

If you are working on your Chapter 5 Independent Study, please post questions to this topic.  Kylee asked the following:

I started on the problems and i understand the pressure stuff in the first section but i don’t understand the unit stuff for problems 27 and 29. Its the exact same type of problem so i’m guessing i kinda need to know what I’m doing. I know the equation to use is P(gas)=P(atm) +( or -) h. But since h is in m or cm and P(atm) is in (atm, torr, Pa, etc.) how do you do that?

One thing that will help you is that the unit of Torr is the same as millimeters of mercury, noted as mm Hg.  On the weather reports on TV, they report this in inches of mercury because the average Americans a) don’t know what a millimeter is and b) don’t much care what the atmospheric pressure is.  Anyways, mm Hg is the same as a Torr so when 1 atm equals 760 Torr, this is also 1 atm = 760 mm Hg.  If your height is given in meters or centimeters, just use your metric conversion expertise and move the decimal.  Also, a few other tips:

• Pay attention to if the manometer is closed or open ended.  Closed-end manometers don’t have anything to do with atmospheric pressure and the pressure of the gas is equal to the height difference of the mercury.  For open-ended manometers, if the gas pressure is more than atmospheric, then the mercury will be higher on the atmosphere side so the height difference must be added to the atmospheric pressure.  If the gas pressure is less than atmospheric, the atmosphere will push more on the mercury and the mercury will be higher on the gas side.  This height must be subtracted from the atmospheric pressure.
• More posted as I receive more questions… 

Good luck!  I hope you are all having a great break and are enjoying the snow!

Final Review Lists December 13, 2007

Chemistry I and Physics will take their finals on Monday, Dec. 17.

        Chem I Review List - Chapter 5 Test Questions for Review

        Physics Review List

Applied Chemistry and AP Chemistry will take their finals on Tuesday, Dec. 18.

        Applied Chemistry Review

        AP Chemistry Review List

Chem II Assignment for Wed. 10/31 October 30, 2007

Eventhough most of you weren’t in class, I didn’t want you to miss out.  Here’s the rundown:

HW #12: pg 870 #56, 59-60, 63-64, 67-68

Be sure to have read over and know your lab for Friday.

You will also be responsible for the concepts in the remainder of Chapter 17.  Specifically pay attention to corrosion of iron and how to prevent it, how an electrolytic cell is different from a voltaic cell, how electrolytic cells are used commercially, and other types of cells.  We will try to finish up Chapter 17 on Tuesday and review what we can.  Our test over Chapter 17 will be Thursday, Nov 8.

Electrochemical Cells October 9, 2007

Check out these sites to help you understand Chapter 17!

http://www.ausetute.com.au/voltcell.html - This is really good!

http://www.blackgold.ab.ca/ict/Division4/Science/Div.%204/Voltaic%20Cells/Voltaic.htm - Super animation link on this site!

http://en.wikipedia.org/wiki/Galvanic_cell

http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch20/electro.php#voltaic

http://chemistry.about.com/library/weekly/aa082003a.htm