Due today: Avogadro's Number
Homework: Moles 1 worksheet (there is a backside!) and Avogadro's Number lab

Hello! We started off class with Lab questions. Remember, on the calculation part of the lab, there are useful facts and figures and irrelevant tid bits down at the bottom of the paper. The purpose of this lab is to give a better understanding of the magnitude of Avogadro's number. If you didn't understand number 1, here is the equation to solve it: 

1 mole of rice × 6.02×10^23 × 56 sec/100 Rice × 60 sec/1 min × 60 min/ 1 hr × 24hr/ 1 day × 365 days/ 1yr. 

Also, Jane, Madison, and Jake measured 1 mole of iron, copper and aluminum. They came out to be pretty close to the atomic mass from the periodic table. You can always simplify Hydrogen to 1 or Nitrogen to 14, but elements like Chlorine can be simplified to 35.5. This is also known as the Molar Mass. It's equal to the numerical value of the average atomic mass, and the units should be grams per mole. Avogadro's number is usually used to measure BIG numbers and put it into scientific notation. (Such as the number of atoms, or molecules.) Mr. Lieberman showed us red liquid in a graduated cylinder. It looked like a small amount of liquid, but there is a mol of water molecules in it.   

Example)
 
1 Mole of CaCl ^2 = 111.1 g/mol 

1 mole Ca × 40.1 g/mol
+ 2moles Cl × 35.5 g/mol = 71 g/mol 
                                        = 111.1 g/mol CaCl ^2 

Here is an example of Avogadro's number from the Homework from Wednesday:

A sample of pure acetic acid, CH^3COOH, contains 1.4×10^23 carbon atoms. How many moles of acetic acid are in the sample?

1.4×10^23 × 1 molecule/2 atoms × 1 mole/ 6.02×10^23 = .116 moles.

ALSO, if you still do not understand Avogadro's number, the mole, and conversions, click here and watch it:http://www.youtube.com/watch?feature=player_embedded&v=AsqEkF7hcII#!


Next scribe is: Benya C