Moles and Avogadro's Number

Amedeo Avogadro

Due Today:  Naming Workshop worksheet
Quiz on Naming Ionic and Covalent Bond and Acids

Due Thursday:  Avogadro's Number worksheet
Due Friday: Avogadro's Number Lab

          After the daily routine of checking the homework Mr. Lieberman started to explain Avogadro's number and the mole using a packet he had handed out. We first learned about an Italian scientist, named Amedeo Avogadro, who conducted a series of experiments, to discover a specific number of atoms, N sub A, that is constant regardless of the element if and only if the mass of the sample of the element in grams is numerically equal to the atomic mass of the element. Knowing Avogadro's number makes it possible to calculate the mass of an individual atom.
Avogadro's number is as follows:

6.022 X 10^23 

There are:

6.022 X 10^23  H atoms in 1.008 g H

6.022 X 10^23 He atoms in 4.003 g He

6.022 X 10^23 S atoms in 32.07 g S

The name given to Avogadro's number is 6.022 X 10^23. A mole represents an enormous quantity and is used as a conversion factor: 

 Here's a sample problem:

How many moles are in 7.8 X 10^24 atoms of carbon?

(7.8 X 10^24) X (1 mole/6.022 X 10^23 atoms) = 12.9525 moles

At the end of class we did an experiment regarding Avogadro's number to further our comprehension of the matter. In this experiment we collected data, based on a rice grain, to use as conversion factors to solve problems using dimensional analysis.

The next scribe will be Josh M.