Chem Class- October 30, 2009

Another lab is coming up, so today Mr. Doktor showed us what we will have to do. First we are going to fill the sink full of water. Then we will submerge a 100 mL graduated cylinder with water in the sink and then invert it, making sure there aren't any air bubbles. After that, we will place the lighter at the bottom of the sink underneath the water and graduated cylinder. We will also release butane from it so the graduated cylinder will fill up with gas. The purpose is to experimentally determine the molar volume of a gas. We will also find out what the mass of the Butane lighter is before the experiment, after the experiment, how much is used in the experiment and calculate the amount of moles of the Butane. After that, as usual, we are to calculate the percent error in our calculation of molar volume and list any factors that may have affected our results.


Notes on Atoms and Molecules.

For Monoatomic elements: A molecule = an element

Molecules and compounds: H2O = 2 "H" atoms in 1 molecule/ 1 "O" atom in 1 molecule

Conversion fator for moles to molecules and vice versa:
6.20 x 10 to the power of 23 molecules/ 1 mol or 1 mol/ 6.20 x 10 to the power of 23 molecules

Eg: How many molecues are there in 0.125 mol of molecules?
# of molecules = 0.125 mol x 6.02 x 10 to the power of 23 molecules/1 mol = 7.53 x 10 the power of 22 molecules.

Oh, and Mr. Doktor broke a wooden board in half!!!!!