Thursday, November 18, 2010

Chapter 4 - Atomic Mass and Avogadro's number - Isabelle Cheng - November 17, 2010

Isabelle Cheng
November 17, 2010
Block 2-2 Chemistry 11
Ms. Chen
Chapter 4 - Avogadro’s Theory and Atomic Masses
The mole is the amount of carbon atoms in 12 grams of carbon. On the other hand, a molar mass is the mass of one mole. For example, a dozen means 12 and so, a mole means 12 grams. Using the periodic table is very necessary for solving these problems. Some examples from using the periodic table is that Iron has an atomic mass of 55.8. Then right away you know that the molar mass of the element is also 55.8g. 
Another example:
AgNO3 - 1 Ag = 1 x 107.9 = 107.9, 1 N = 1 x 14.0, and 3 O = 3 X 16.0 = 48.0 and all of it together is 169.9 grams which means that the molar mass is 169.9 grams.
We also need to include unit conversions in these problems. 
For example, we need to use this equation:
1mol___     molar mass of X
molar mass of X           1mol

Avogadro’s number:
- 6.022 X 10 ^ 23
- large number 
video

No comments:

Post a Comment