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					           AP Chemistry Information & Summer Assignment 2010
Introduction
Congratulations on your decision to take Advanced Placement Chemistry! This class has the potential
to be one of the most fun & rewarding classes that you will take in high school. However, please be
advised that many people have found AP Chemistry to be a particularly challenging course with a
particularly challenging exam, even when compared with other AP courses and AP exams.
Remember also that AP classes are taught as college courses—not just college-level courses, but actual
college courses. This means that:
        I will do as much as I can to help you learn, but you and you alone are responsible for learning
         and understanding everything covered in class.
        I will tell you when everything is due, but I won’t chase after you. If you were absent and you
         need to turn in an assignment late, you need to remember to show it to me; do not assume I will
         ask you for it.
        If you’re having trouble with something, you need to be proactive about learning it, either by
         coming in for help after school, consulting with your classmates, or by getting outside help. This
         expectation is effective immediately, and it applies to this summer assignment. Remember—your
         job is to succeed; my job is to do everything in my power to help you be successful. Don’t ever
         hesitate to make me do my job so you can do yours!
The goals of this summer assignment are to make sure you haven’t completely forgotten Chemistry I, to
give you a “warm-up” for AP Chemistry, and to make you question, anyone who’s not serious about
doing the work.
The assignment consists of some challenging problems that combine multiple concepts from Chemistry
I, an experiment, and a practice exam. The challenging problems and experiment write-up are due on
Tuesday August 24, 2010.* No exceptions! You must come to the first day o f class with them in order
to remain enrolled in AP Chemistry. We will review on Tuesday and Wednesday. The exam is practice
for the entrance exam, which will be given on Thursday, August 26, 2010.* You must pass the entrance
exam (60% or better) to remain enrolled in the class.
You may work with your friends (or enemies) in the class, as long as you list the names of the people
you worked with and each person turns in a separate copy. You may also ask me for help. You can find
me online at:
           Email: digennaroj@pcsb.org
           Website: use the Chemistry I and/or AP Chemistry Moodle site;
                    login with guest access.
Warning: don’t leave the assignment until the week before school starts—if you do, you’ll be sorry!

Recommended Supplies
I recommend the following supplies for success in AP Chemistry:


*
    If AP Chemistry does not meet on Tuesday August 24 and Thursday August 26, the assignment will be due on the next
    class day after August 24, and the exam will be given two days following.
AP Chemistry Information & Summer Assignment 2010                                                   Mr. Bigler

          Composition book for use as a laboratory notebook. Your lab notebook must have pages that are
           permanently bound into the notebook and cannot be easily removed.
          Scientific calculator. It does not need to be a graphing calculator, though you are welcome to
           use a graphing calculator if you already have one.
          AP exam review workbook. I recommend the Barron’s or Princeton Review AP Chemistry
           book.
           .

Entrance Exam
There will be an entrance exam the first week of school. You will be required to pass an entrance exam
(with a score of 60% or better) given on Thursday, August 26, 2010† in order to remain enrolled in AP
Chemistry. If you receive lower than 60% you and your parents will be notified. The exam will consist
of questions taken from an international competitive exam intended for students who have completed a
first-year high school chemistry course. It will be similar to your Chemistry I final, with more emphasis
on stoichiometry.

Summer Assignment Part 1: Homework Problems
The following three problems combine concepts from Chemistry I. They are intentionally more
challenging than problems you have likely encountered in previous classes.

For each problem (and subsequently throughout the year), you must show all of the steps that lead from
the question to your answer, regardless of whether you do the work on paper, on your calculator, or in
your head. (Show as much detail as you would for a mathematical proof.)

       1. A rigid tank is filled part-way with water. After adding the water, the tank contains 15.0 L of air,
          the temperature is 26°C, and the total pressure inside the tank is 99.7 kPa. If the temperature is
          lowered to 21°C, what is the new pressure inside the tank? (You may assume that air and water
          vapor behave as ideal gases, and you may neglect any changes in the volume of the liquid due to
          thermal expansion.)
          The vapor pressure of water is 3.36 kPa at 26°C, and 2.49 kPa at 21°C.




†
    As above, if AP Chemistry does not meet on Tuesday August 24 and Thursday August 26, the assignment will be due on
    the first class day on or after Tuesday August 24, the exam will be given two days following.

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AP Chemistry Information & Summer Assignment 2010                                     Mr. Bigler

   2. Powdered sodium hydrogen carbonate (4.75 g) is added to 125 mL of a 0.225M solution of
      hydrochloric acid in a sealed 2 L soda bottle (with an actual capacity of 2.15 L). The following
      (unbalanced) chemical reaction occurs:
                           NaHCO3 (aq) + HCl (aq) → NaCl (aq) + H2O (ℓ) + CO2 (g)
      The soda bottle is full of inert argon gas at a pressure of 102.5 kPa prior to the reaction. The
      reaction is endothermic, and cools the entire contents of the soda bottle to 2.0°C. What is the
      pressure inside the bottle after the reaction is complete.
      (You may neglect the vapor pressure of water at 2°C in your calculations. You may also neglect
      any effects from the CO2 dissolving in the solution or reacting to form carbonic acid.)

   3. Permanganic acid (350 mL of a 2.0M aqueous solution) is reacted with 2.0 L of 2.0 N
      hydrochloric acid, producing aqueous manganese (II) chloride and chlorine gas. The
      hydrochloric acid was made with pure radioactive chlorine-33, which has a half-life of
      37.24 minutes and undergoes β− decay. The reaction is conducted in a sealed 25 L vessel at an
      initial pressure of 99.5 kPa. The vessel is kept at a constant temperature of 25°C throughout the
      reaction. What is the pressure inside the vessel after 75 minutes?
      Notes:
          a. This is a redox reaction, which you will need to balance. Note that because the reactants
             are acids, you may assume that the reaction is happening under acidic conditions.
          b. This is also a stoichiometry problem. Because amounts are specified for both reactants,
             you will need to use the balanced equation to determine which reactant is limiting, and to
             determine how many moles of chlorine gas are produced.
          c. Because 33Cl undergoes β− decay, this is also a radioactive decay problem involving
             half-life. The final number of moles of gas in the container will depend on how much of
             the chlorine decays, and whether the product of decay is a solid, liquid, or gas. (Note that
             chlorine atoms from the aqueous manganese (II) chloride solution and the chlorine gas
             (and the hydrochloric acid, if it turns out to be the non-limiting reactant) are all
             undergoing radioactive decay.)
          d. This is a much more complex problem than I expect you to be able to solve. However, I
             fully expect you to make some progress toward solving it. We will hold an in-class
             discussion about this problem during the first week of class, and you will be graded on
             your participation in that discussion.

          For the purpose of simplifying this problem, you may assume that all gases behave ideally,
          that the reaction goes to completion (neglect equilibrium calculations), and that you do not
          need to worry about what happens when one molecule of a diatomic gas decays—assume
          that the decay process for Cl2 produces a chloride radical, which rapidly combines with a
          second chloride radical to produce a molecule of chlorine gas. You may also neglect any
          shift to the equilibrium (because of Le Châtelier’s principle) caused by the radioactive decay
          of the chlorine atoms.




Summer 2010                                                                           Page 3 of 5
AP Chemistry Information & Summer Assignment 2010                                       Mr. Bigler

Summer Assignment Part 2: Laboratory Experiment
Alka-Seltzer tablets contain a mixture of aspirin, sodium hydrogen carbonate (sometimes called sodium
bicarbonate), and citric acid. When Alka-Seltzer tablets are dissolved in water, an acid-base reaction
happens between the bicarbonate ions and hydrogen ions from the citric acid, forming carbon dioxide
gas, according to the following (unbalanced) chemical equation:

                                HCO3− (aq) + H+ (aq) → H2O (ℓ) + CO2 (g)

Your assignment is to determine the mass of NaHCO3 contained in one Alka-Seltzer tablet. I suggest
the following plan:

    1. Measure the volume of CO2 gas that evolves when you dissolve the tablet in water.
    2. Use the ideal gas law to determine the number of moles of CO2 evolved.
    3. Use stoichiometry to determine the mass of NaHCO3 that the Alka-Seltzer tablet contained.

You should obtain a composition notebook for your experiment write-up.

This will be your first experiment for AP Chemistry. Please leave the first two pages blank for a table of
contents.

Everything you do regarding this experiment must be recorded in your notebook in ink.

Your write-up should include the following sections:

     Objective: a brief (one-sentence) description of what you are trying to accomplish
     Plan: a brief outline of how you plan to do the experiment. (The three steps listed above could
      serve as your experiment plan.)
     Procedure: your actual procedure, to be written down as you perform the actual experiment.
     Data & Observations: any measurements you take or other data you record
     Analysis: calculations, conclusions, percent error, and possible sources of error.

You will need to provide the Alka-Seltzer tablets. You may use any other materials you like, such as
balloons, plastic bags, buckets, etc, but you MUST record all of your materials.

For the “accepted value” in your percent error calculations, use the mass of sodium bicarbonate labeled
on the package.



Problems and Questions

If you have any problems or questions about the assignment, do not hesitate to send me an email. I will
reply with suggestions, comments and answers as soon as possible.

If you do not know how to carry out these calculations, please refer to one of the AP guides. They give
tutorials on how to compute these.

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AP Chemistry Information & Summer Assignment 2010                        Mr. Bigler

With hard work and dedication we will have a great AP Chemistry class!




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