Wednesday, October 20

Mr. H started off the class by telling us why not to tell mole jokes because they are molelitically incorrect. He then began to tell some mole jokes about Avogadro and his number, 6.022*10^23. After cracking some mole jokes, Mr. H told us to take out our packet and turn to pages 6 and 7.

We began to review the molar mass of compounds and the mole and atomic mass. The first problem we started on page 7 was 7 and our task was to find the formula for the compound and then determine the molar mass of the compound. In order to solve this problem, you must first figure out the formula for the compound barium nitrate. Barium has a plus 2 charge and nitrate has a minus one charge, and you have to switch these numbers due to the principal of electrical neutrality. The formula would be Ba(NO3)2. Then you must find the atomic mass of barium which is 137.33, nitrogen which is 14.01 * 2=28.02, and oxygen is 16.00 * 6=96. Now you add all of them together and you get 361.35g/mol.

After we finished this, Mr. H taught us how to do mole conversions on page 9. The most important part to remember is the relationships between Particles(atoms, molecules) <==> Moles, use Avogadro's number, Moles <==> Mass, use molar mass.
The answers to the three problems are:
1. 12.16mol

2. a. 1.48 * 10624

b. 98g/mol

3. 2.59 * 10^22 molecules

Then we went to the science computer lab to work on our webassigns for the rest of the period.
HW: 3.2 Molecules<==> Moles<==>Mass Part 1 due Friday, Part 2 due Monday and Unit 3 Delicious Bookmark due Tuesday.