(Some Screencastomatic videos require Java 1.5 or later. Check your Java; others are HTML5)
Unit 3: Measurement, Percent Composition/Emp. Formula,

What is the difference in the accuracy of a beaker and a graduated cylinder? Why is one preferable to the other if accuracy is the goal? How do you convert from one unit to another? What is the mole anyway? What does it have to do with compounds? How do chemists know how much of anything to use in a chemical reaction?

Textbook Chapters:
1 & 3 
3.4 Formula Calculations
 I can determine percent composition of compounds by recognizing role of formula mass and applying both ideas appropriately when solving various problem types
 I can determine empirical formula and molecular formula from both percentage and mass information, including application of combustion analysis
3.4a Hydrate Composition
Exploration Objective
 What percentage of the hydrate is water?
 How reliable are your results? How do you know?
 What amount of water would be 'lost' if you used 6.0g of hydrate?
 How would your results change if some of the hydrate/anhydrous solid were spattered out? Why?
3.4b Percent Composition, Empirical Formulas, Molecular Formulas
There will be a few different vodcasts here. The first is just introducing percent composition; the second one is empirical/molecular formulas. We'll go into detail on the mole when we start stoichiometry.


Quiz #2: Sections 3.4
3.5 Calculations with Equations
 I can utilize balanced chemical equations within stoichiometric calculations
 I can explain and calculate percent yield
Still unsure about a mole? Watch the video below, then follow this link and click on the 'Think' tab and answer the questions to the right.


3.5b White Powder & Unknown Liquid
Exploration Objective
 What is the mass relationship between the solid and the gas?
 Does the mass relationship apply to any/all chemical reactions?
 Is there a molar relationship? Why or why not?
3.5c Stoichiometry
from Seattle Weekly blogs
After going through the Bean Lab (modeling the mole), you should have a general understanding of the mole.
In these notes, you get a bit more of a breakdown; more importantly we see how this applies to stoichiometry.
The ability to convert one substance into another is not new, this is a chemical reaction: you did this when you produced carbon dioxide gas by combining vinegar and baking soda. The difference is, now, you can take an amount of baking soda and determine the amount of carbon dioxide gas yielded. This is stoichiometry.
In these notes, you get a bit more of a breakdown; more importantly we see how this applies to stoichiometry.
The ability to convert one substance into another is not new, this is a chemical reaction: you did this when you produced carbon dioxide gas by combining vinegar and baking soda. The difference is, now, you can take an amount of baking soda and determine the amount of carbon dioxide gas yielded. This is stoichiometry.
(YouTube)


Here are several YouTube videos to help out: (1) sample mole conversion problems; (2) a reminder of the steps to solve stoichiometry problems; (3) a stoichiometry practice problem; (4) another stoichiometry practice problem.
Quiz #3: Sections 3.5
3.6 Limiting Reactants in Stoichiometric Calculations
 Explain what a limiting reagent is and it's role in determining maximum product formed
3.6a White Powder & Unknown Liquid
Exploration Objective

3.6b Limiting Reactants PhET
Perform the simulation using the directions, Basic Stoichiometry PhET Lab, in Dropbox.

3.6c Limiting Reactants
from HauteLiving.com
Limiting reactants are really simple...you just have to remember it's based on stoichiometric amounts; and, the amount of product yielded is always based on the least produced. The next item to remember is if you are given amounts of more than one reactant, it must be a limiting reactant problem.
Just think of a cheeseburger: it takes 1 patty, 2 buns, 1 cheese. If you have 20 patties, 19 cheese, and 22 buns, how many burgers will you really be able to make?
[20 patties = 20 burgers, 19 cheese = 19 burgers, 22 buns = 11 burgers; therefore, only 11 burgers can be made. The rest is excess.]
Just think of a cheeseburger: it takes 1 patty, 2 buns, 1 cheese. If you have 20 patties, 19 cheese, and 22 buns, how many burgers will you really be able to make?
[20 patties = 20 burgers, 19 cheese = 19 burgers, 22 buns = 11 burgers; therefore, only 11 burgers can be made. The rest is excess.]


Quiz #4: Sections 3.6