Tuesday, August 31, 2010

Review for the Chapter 3 Exam

On the events calendar for August 31st, I have placed the file (Power Point) for the solutions to the three old AP Chemistry problems that we have been using as our prime review for the Chapter 3 exam that you will take on Thursday, September 2nd, 2010. Some of the solutions are different than what we performed in class, but that is o.k. There is usually more than one way to solve a problem. Remember, tomorrow, we will be in the computer lab in the library. You can use the time to review and work on WebAssign. Have a good night.

Monday, August 30, 2010

Schedule for the week of 8/30-9/3

I just want to give you some insight to the schedule for the week. Tomorrow (Tuesday, 8/31) we will work on the review packet in class of old AP problems. This will be your review for the exam, which will be all written and consist of old AP problems. You may be given parts to the question on the exam that we have not covered yet. I will supply any information to those parts of the test that you will need to use later in the problem. This is just like the review that I gave you. Wednesday is a late start day, so I am going to give you the time to work in class. I will try and supply computers so you can log onto WebAssign and work on your homework. Thursday will be the exam. I hope to have the tests graded by Friday and we can go over them. I will make the Chapter 3 WebAssign due on Saturday, Sept. 4th to ensure that you have the full day after the exam to finish any remaining problems.

Sunday, August 29, 2010

GRADES HAVE BEEN UPDATED!!!

I have just updated grades. Some individuals are missing minor assignments (like the signed Lab Safety Contract and Class Policies and Procedures), but because there are very few grades to buffer a bad grade, those individuals have very poor (I'm talkin' "F"!!) grades. Please look at your grade and get the required material to me. The Lab Safety Contracts and Class Policies and Procedures can be found on my teacher pages. I think that activities start taking grade reports this Wednesday for eligibility, so the sooner the better for rectifying the situation.

Copper (?) Iodide Lab Write-Up Due Tomorrow & Preparation

Remember, that tomorrow your lab first write-up for the year is due. Just as we discussed in class, you are not only doing the write-up for a grade in may class, but you are also auditioning for a college or university to receive lab credit if you end up passing the AP Chemistry test next spring. My big area of emphasis on the lab report will be the SEE's and the conclusion. Please make sure that your SEE's address situations that are plausible to your results. If you are overly generic, be prepared to receive no points for your SEE's portion of the report. If you are very specific in your plausible explanation, but contradict your findings, you will receive some credit. So it is better to be intricate and misguided than generic and not address anything of substance. The conclusion must address if the theory was met. Remember, you only have two choices for a plausible formula for copper (I or II) and iodide. Please also include a statement on how you would improve the lab. Just like any other report for any other class, you may want someone to read it for you and critique your work.

In the Chapters portion of my web page, I have posted two links for Vodcasts (new term, catchy, isn't it??) One is for empirical formula determination through combustion analysis and the other is how to determine a limiting and excess reactant. Before tomorrow, (Monday, 8/30), please watch the video on how to determine limiting and excess reactants as a refresher. I will cover the material quite quickly, so the Vodcast will allow you to review / learn at your own pace.

Finally, a AP Chemistry student emailed me with a helpful hint for WebAssign and entering scientific notation numbers. If for some reason (this is a random example) you needed to type Avogadro's number into WebAssign, instead of 6.02 x 10^23, you need to type it in just like it would appear as an answer on your graphing calculator: 6.02E23. If you had a small decimal number, you would type (example): 3.87E-7. Remember to keep plugging away at the WebAssign work. We will probably have a test later this week, so the work will probably need to be done by Friday. Also, your will be getting a review packet tomorrow (Monday, 8/30) in class and I will require the answers to be reported on WebAssign PRIOR TO THE CHAPTER 3 EXAM.

Thursday, August 26, 2010

Empirical Formula Determination Through Combustion Reactions and Extra Credit Opportunity

Please complete the problem shown below. Have the solution ready to submit at the beginning of class on Friday, August 26th, 2010. To save time and effort on the problem, notice that the measured values are reported in milligrams. Therefore, feel free to work in the unit of millimole. The ratios all remain the same.

Also, if you would like 10 points extra credit towards your homework grade, bring in a 4-pack of AAA batteries. I will stockpile the batteries and if you need batteries for your calculator at any point this year, you can take a pack from the stockpile.

At the end of class today, there was a queston of what to do with decimals (fractions) once the moles of each element in the compound have been divided by the lowest mole value when determining an empirical formula. If a value is rougly nine tenths (X.9) or one tenth (X.1), then feel free to round up (X.9) or round down (X.1). For other decimals or fractions, use the examples below for how to convert the fraction to a whole number. Remember, elements combine in small whole numbers. **The use of "X" "Y" and "Z" are generic to represent any element.

  • 1/2 --> (X .5)x2 --> {Example (Y2Z3.5 )2 --> Y4Z7}
  • 1/3 --> (X .33)x3 --> {Example (Y1.33Z1)3 --> Y4Z3}
  • 1/4 --> (X .25)x4 --> {Example (Y1.25Z1)4 --> Y5Z4}
  • 1/5 --> (X .2)x5 --> {Example (Y1Z3.2)5 --> Y5Z16}
  • 2/3 --> (X .67)x3 --> {Example (Y1Z2.67)3 --> Y3Z8}

The fractions represented above are the most common (if not only) fractions you will encounter when doing an empirical formula determination.

Tuesday, August 24, 2010

Game Day Tomorrow!!

Tomorrow is the first lab of the year. If you will allow me to make an analogy, laboratory day to a chemistry student is like game day to an athlete. Just like the game is the reason for all of the practice that an athlete endures, laboratory work is the reason for learning all of the theory during lecture. You are going to "hopefully" prove all of the theory correct.

Your homework for this evening was to finish the pre-lab question pertaining to the second lab scenario given. Does the the empirical formula of the copper and iodine compound change if the atmospheric pressure changes? We will go over the solution at the beginning of class tomorrow. Remember, keep working on the Chapter 3 WebAssignment.

Monday, August 23, 2010

Beginning of Chapter 3

It is suggested that you read the first five sections of Chapter 3. Today, we covered reactions (writing and balancing), molar (atomic) mass determination of compounds, and simple mole conversions. You should be able to complete through #5 on the WebAssign assignment for Chapter 3. I have set the due date to Monday, September 13th. We will finish Chapter 3 well before that date, so the due date will change to one day after the Chapter 3 test. Also, we will be incorporating old AP Chemistry test written problems into Chapter 3. I will be creating another assignment for the answers to those problems.

Tomorrow, you will be taking the 20 question (true / false) safety quiz. This needs to be completed prior to doing the first lab of the year. We will be doing a pre-lab activity tomorrow over how to determine an empirical formula. On Wednesday, 8/25/2010, we will be performing our first lab of the semester. I will also be going over lab reports tomorrow. PDF files of the lab and the lab report format can be found on the AP Chemistry calendar under the date of 8/24/2010.

Please keep your questions coming via email so I can make of plan of what questions need to be addressed prior to class starting.

Friday, August 20, 2010

Nuclear Reactions (Transmutations)

The last two problems in the Chapter 2 assignment has to do with material presented in Chapter 21 of the book. The questions cover sections 21.1 through 21.3, which deals with radioactive decay of isotopes. It would be a good idea to read over those three sections. Also, if you go to the AP Chemistry calendar, there is a link on August 20th for a Power Point that covers the material covered in the three sections of Chapter 21.

I have also supplied a link for a short movie (9 minutes) on YouTube that covers the basics of nuclear decays / reactions. It is old, but does cover all of the basic points of nuclear transmutation / decay very well. Keep the questions coming via email if any of the questions from WebAssign give you problems.

HOLD THE PHONES!! STOP THE PRESSES!! I HAVE FIGURED OUT HOW TO MAKE A QUESTION THAT STUDENTS CAN ANSWER ON WEBASSIGN!! O.k., it is not that big of a deal, but I did figure out how to make an answer block for questions #16 and #17 on the Chapter 2 WebAssign homework. Cross your fingers and hope that it works.

Thursday, August 19, 2010

Mass Spectrometer and Associated Material

Click on the link for the virtual mass spectrometer demonstration if you would like to see how a "mass spec" operates.

A link to the Average Atomic Mass / Percent Abundance worksheet is on the AP Chemistry calendar for August 19th if you need another copy. We will finish the percent abundance practice problem first thing in class tomorrow. I will be requiring that you put your answers to questions #16 and #17 on the WebAssign chapter 2 assignment. Please wait to do so until I have configured the site to take the answers and grade them. Also, because I have added more problems to the chapter 2 assignment, I have extended the due date to Tuesday, August 24rth, 2010.

Tuesday, August 17, 2010

Chapter 2 Power Point Available

If you would like to download a Power Point file for chapter 2 in the book, one is available.
  • go to my teacher page on the HHS site (Brueckner, Corey)
  • go into the AP Chemistry page
  • click on AP Chemistry calendars
  • on Tuesday, August 17th is the link to the file
The first 30 or so slides deal with material covered in the first year course about the evolution of the atomic model. This material will not be covered. The last half of the presentation deals with the material from chapter 2 that is covered in the WebAssign homework. It does a very good job of covering types of compounds, naming of compounds, and writing compound formulas. It is suggested that you work on problems 1 through 9 in WebAssign. We will finish going over examples for the homework assignment tomorrow. Please email me with specific questions on problems or see me personally. If there is enough interest in a particular type of problem, I can make a podcast covering the material and go over it in class.

Sunday, August 15, 2010

First Day of Class

Welcome to Mr. Brueckner's AP Chemistry class. I hope that we have a really good year together. You need to complete the following by Friday, August 20th, 2010.
  1. Print a copy of the Classroom Policies and Procedures found on Mr. Brueckner's Chemistry page. The copy needs to be signed acknowledging that you and your parent(s) / guardian(s) are aware of class expectations and grading policies.
  2. Print a copy of the Lab Safety Agreement, which can be found on Mr. Brueckner's homepage. The agreement must signed by you and your parents. Read over the safety contract and be prepared for a 20 question lab safety quiz on Friday, August 20th, 2010.
You also have a deadline for the first WebAssign assignment. Chapter 2 needs to be completed by Monday, August 23rd, 2010.

First Week, What to Expect

Your first assignment on WebAssign has been posted. You need to complete it by Monday, August 23rd, 2010. There will be no unit test over Chapter 2 in the book. You only need to complete the homework assignment for Chapter 2. There will be a quiz related to material in Chapter 2 that is not covered by the homework on WebAssign.