Take-Home Quizzes: Learning to Learn in
Introductory Chemistry - by Holly Walter Kerby and
Examples of Problems
Connection Question 1
Freeze-separation pops: Do this activity in the comfort of your own kitchen. Record your observations, answers and explanations on the following page.
- Fill a paper or plastic cup with tap water. Stir in one to three teaspoons of Kool-Aid, iced tea mix, lemonade mix or something like that (plain old sugar if you don't have anything else), and stir until it all dissolves. If it won't dissolve, add a bit of water until it does. In other words, you want a fairly concentrated solution without having any excess "stuff" on the bottom on the glass.
- Put the mix in the freezer. Check it every couple of hours until the solution is frozen. Which part of the solution freezes first, the top, bottom, middle, or does it all freeze at the same time?
- When it is frozen solid, run hot water over the glass, remove the icy chunk, and examine it. Is the mix you added to the water dispersed evenly throughout the chunk? Describe the appearance of the chunk. Now do what chemists never get to do in the lab-- delicately lick various parts of the chunk to determine what part tastes strongest. Record your observations.
- Explain how freezing can be used to separate components of a mixture using the activity you just did as a reference.
Connection Question 2
You are watching a TV program about our solar system with a friend. The program narrator mentions the sun is composed primarily of hydrogen and helium. Your friend turns to you and says, "How do they know that?! They haven't been to the sun! How could they possibly know what elements are in the sun?" You suddenly remember looking at emission spectra the other day in chemistry class, and realize you know how they know. Explain it to your intelligent, but science-illiterate friend in your own words.
You have been assigned to choreograph a short, educational performance piece titled "Dance of the Atoms." The purpose of this piece is to physically represent the arrangement of and attraction between atoms in a solid, liquid, and gas, and to dramatize the changes that occur during melting and boiling. You may have a cast of 6 to 9 people; they will be the atoms. The play/dance should open with the cast arranged as a solid at 20 degrees below the substance's melting point. When the curtain falls, the substance should be a gas that is heating up rapidly. The choice of music is yours.
If I grade this question, I will evaluate your script based on accuracy, completeness and detail. I will not penalize you if your script is boring.
Write your script on what's left of this page and the next one, too. Or, if you wish, attach a separate page. Please write legibly and use complete sentences.
The best script (based on the criterion mentioned above, plus all sorts of aesthetic considerations) will be produced in class and preserved on videotape. The choreographer(s) will receive 5 extra credit points and a all-expenses-paid trip to Stoughton. (Just kidding about Stoughton.)
In case you are wondering, I am not losing my mind.
Correct your UNIT 2 exam. Follow these instructions:
*TURN IN THIS SHEET PAPER-CLIPPED TO THE FRONT OF YOUR EXAM #2.
- For Part I, Problems and Fill-Ins-
Using a different color pen or pencil than you used to take the exam, correct every single item you missed directly on the original exam form. In the margin next to the problem, tell me why you think you missed it.
- For Part II, Multiple Choice-
Pick five multiple choice questions that you missed. Circle the correct letter on the original exam form (not the scantron) and then, in the margin next to the problem, write a sentence to tell me why you think you missed it. If you missed less than five multiple choice questions, do all of them.
- Is there a pattern to your mistakes and/or why you think you made them? What is it?
- Write a paragraph below telling me how you feel about your performance on this exam, and WHY you think you performed as you did. Is there anything you will change in your preparation for the UNIT 3 exam?
Trouble Spot Question
(A) Draw Lewis dot structures for the following substances:
|I. NaF ||II. CF4 |
|III. F2 ||IV. NF3 |
Symbol Question 1
Figures A, B and C below represent three flasks. Using circles of your own choosing to represent atoms of the appropriate elements, fill flask A with water vapor, B with a mixture of hydrogen gas and oxygen gas, and C with a mixture of carbon dioxide, oxygen gas and nitrogen gas. Be sure to include a key to tell me how you are representing all the atoms you draw.