Chemistry Study Guide #6
1/5/04
- Avogrado- 1776-1856. Italian. Laws of Definite and Multiple Proportions.
- Avogrado’s Principle- equal volumes of all gases at the same temperature and pressure contain same number of molecules
- Avogrado didn’t discover the mole, but his principles were used
A mole is simply a number
ç (pi) = 3.14159
Dozen = 12
Gross = 144
Ream = 500
Mole = 6.0221367 x 10²³
- “1 mole is the amount of substance which contains as many particles as there are atoms in exactly 12 g of carbon-12.”
- Atomic weight is measured in grams per mole (g/mol)
o Ex. Carbon weighs 12.0107, so 12.0107 g. carbon have 1 mol of particles
- For compounds, add elements together
o Ex. CuSO4—4 x 16.00 + 1 x 32.07 + 1 x 63.55 = 159.62 g/mol. There will be 1 mol of particles in 159.62 grams of CuSO4
The molar (or gram- formula) mass for any substance is equal to the number of grams of the substance in one mole.
8-1
Relative atomic mass- accounts for isotopes- not exact
Molar mass- numerically equal to atomic mass. Unit is g/mol
Single- atom mass (in grams)- molar mass/ mol