A. What is the Mole?
A counting unit Similar to a dozen, except
instead of 12, it’s 602 billion trillion 602,000,000,000,000,000,000,000
6.02 X 1023 (in scientific notation) This number is named in honor
of Amedeo Avogadro (1776 – 1856)Amedeo Avogadro (1776 – 1856),
1 mole of hockey pucks would equal the mass of the moon!
A. What is the Mole?
1 mole of pennies would cover the Earth 1/4 mile deep!
1 mole of basketballs would fill a bag the size of the earth!
How does a Mole relate? 1 Mole of anything has 6.02 x 1023
particles If I had 1 mol of cookies, how many
cookies would I have? If I had 1 mol of cars, how many cars
would I have? If I had 1 mol of Aluminum, how many
atoms I have? Note that the NUMBER is always the
same, but the MASS is very different!
1 mole of Carbon = 6.02 x 1023 atoms (Individual
elements are measured in atoms)
1 mole of H2O= 6.02 x 1023 molecules (Covalent
compounds are measured in molecules)
1 mole of NaCl = 6.02 x 1023 “formula units”
(Ionic compounds are measured in ions)
6.02 x 1023 Na+ ions and
6.02 x 1023 Cl– ions
The “Units” of MolesThe “Units” of Moles
1. Number of atoms in 0.500 mole of Ala) 500 Al atoms
b) 6.02 x 1023 Al atomsc) 3.01 x 1023 Al atoms
2.Number of moles of S in 1.8 x 1024 S atomsa) 1.0 mole S atomsb) 3.0 mole S atomsc) 1.1 x 1048 mole S atoms
Learning CheckLearning Check
Molar Mass Describes the mass (how heavy) 1 mole of
an element or compound is.
Atomic mass tells the:
Atomic Mass Units (AMU)
Used to determine the mass of a single
element.
Grams per mole (g/mol) used to describe the mass of one mole of a
chemical compound.
Typically rounded to 2 decimal places
Find the molar mass – Round to two decimal places. It is
important for significant digits!
Learning Check!Learning Check!
A.1 mole of Br atoms
B.1 mole of Sn atoms
= 79.90 g/mol
= 118.71 g/mol
Molar Mass Examples for molecules and compounds: Water
sodium chloride
H2O
2(1.01) + 16.00 = 18.02 g/mol
NaCl 22.99 + 35.45 = 58.44 g/mol
Molar Conversions (Road Map)
molar mass
(g/mol)
Gram Gardens
Mole Island
Particle Palace
6.02 1023
(particles/mol)
Moles to Grams
How many grams of oxygen are in 0.25 moles of oxygen?
0.25 mol O 16.00 g O
1 mol O= 4.0 grams O
Moles to Grams
How many grams of carbon are in 3.45 moles of carbon?
3.45 mol C 12.01 g C
1 mol C= 41.4 grams C
Moles to Particles
How many molecules are in 2.50 moles of C12H22O11?
2.50 mol6.02 1023
molecules
1 mol= 1.51 1024
molecules C12H22O11