Chapter 9: Stoichiometry
Stoichiometry is the process of calculating the quantities of reactants and products in chemical reactions. The word stoichiometry comes from the Greek word stoikheion, which means "element," and the suffix -metry, which means "process of measuring," so stoichiometry literally translates to "the process of measuring elements."
Section 9.2: Chemical Calculations
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The Mole: Avogadro's Number and Stoichiometry
This video from Professor Dave Explains starts by explaining moles and at 2:43 begins to explain stoichiometry. He even has practice problems built into the video! |
Section 9.3: Limiting Reagent and Percent Yield
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Limiting Reagents and Percent Yield
Professor Dave explains limiting reagents in the first 2:45, goes on to explain percent yield, and finishes with a practice problem. He packs a lot into 4.5 minutes! You'll need to pause the video in order to benefit the most from it. |
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Practice Problem: Limiting Reagent and Percent Yield
Professor Dave presents a sample problem and then shows multiple ways to solve it. |
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Limiting Reactant (Reagent) Practice Problem
Tyler DeWitt presents a problem and shows a solution. He works slowly and methodically. |
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Limiting Reactant (Reagent) Practice Problem (Advanced)
Tyler DeWitt presents a slightly more advanced practice problem and shows a solution. |
Chapter 10: States of Matter
Section 10.1: The Nature of Gases
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Principal of the Water Barometer and Hydrostatic Pressure
Here's a cool demonstration to show how high regular atmospheric pressure can push water in a vertical tube. Units of Pressure
1 atm = 101.325 kPa = 760 mm Hg = 760 Torr 1 bar = 100,000 kPa SI unit of pressure: pascal (Pa) = newton per square meter Condensation and the Power of Atmospheric Pressure
This is the demonstration I did in class, but this time it worked. I recommend you try it at home! One tablespoon of water was added to the otherwise empty Diet Coke can. The Waterloo can was dry. Both cans were heated, and the water was allowed to boil for about a minute. Using tongs, each can was inverted into a bowl of ice water. |
Section 10.2: The Nature of Liquids
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Evaporation and Condensation
This cartoon illustrates evaporation and condensation by considering a fishbowl. |
Section 10.3: The Nature of Solids
Section 10.4: Changes of State
Chapter 11: Thermochemistry--Heat and Chemical Change
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New for 2024: Above are the labels for puffcorn and peanuts. On the left is the label for marshmallows.
Phase Changes: Exothermic or Endothermic
Tyler DeWitt explains this simply and clearly. Near the end (at 5:55), he gives values for the heat of fusion and heat of vaporization of water. The value he gives for the heat of vaporization of water does not agree with our textbook, which I believe is correct. Regardless, this is a great video to guide you in thinking about phase changes. Exothermic or Endothermic?
Heat is going out of the fire, and heat is going into the beaker above it. Is the process exothermic or endothermic? It depends on your point of view. |
Chapter 12: The Behavior of Gases
Air Bags: Beyond the PEP Lab
Since our lab is about making an air bag, it seems fitting that we learn about the chemistry used in automotive air bags. The gases in air bags have changed over the years, but they have never used vinegar and baking soda. Here is an article about the history and chemistry of air bags. |
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Absolute Zero and Charles's Law
Tyler DeWitt explains how absolute zero can be found by measuring the volume of a sample of gas at lower and lower temperatures and extrapolating. He uses a "magic" balloon and fictitious data to explain. In the video directly underneath, a science teacher uses a real sample of air in a syringe to do the same thing. She also gives some of the history behind Charles and Kelvin, the men behind Charles's Law and the Kelvin temperature scale. |
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Dalton's Law and Partial Pressure
Professor Dave offers a basic explanation of Dalton's Law. |