Download The Mole Notes - Mercer Island School District

The Mole
Chapter 10
Counting Matter
Matters
(and breakout the calculators and
periodic tables)
Scientific Notation (you need to know
this before we begin)
• Another way to write
large numbers
1000 =
• 1 x 103
 1, 000, 000 =
• 1 x 106
.001 =
• 1 x 10-3
.000001 =
• 1 x 10-6
Write the following in Scientific or
Regular Notation
• 700
• 7 x 102
• .0054
• 5.4 x 10-3
• 3.60 x 105 seconds
• 360,000 seconds
• 5.4 x 10-5 g/mL
• .000054 g/mL
The Hope Diamond is BIG
• Write the scientific notation
for the following about the
Hope Diamond:
– There are 460, 000, 000, 000,
000, 000, 000, 000 C atoms
– 4.6 x 1023 atoms of C
Move the decimal left 23 times
– The mass of a C atom is
0.00000000000000000000002g
– 2 x 10-23 g per C atom
Move the decimal right 23 times
Adding and Subtracting Sci. Not.
• To add or subtract the
exponents must be the
same
1017
1.50 x
+ 6.5 x 1016
• This should be…
1.50 x 1017
+ 0.65 x 1017
2.15 x 1017
• Add
•
•
•
•
•
3.40 x 106
+ 6.50 x 107
6.84 x 107
Add
3.40 x 10-6
+ 6.50 x 10-7
4.05 x 10-6
Subtract
3.4 x 107
- 6.50 x 106
2.75 x 107
Multiplying and Dividing Sci. Not.
• A 2 step process
(1 x 103) x (5 x 102)
Multiplication:
• Multiply Coefficients
1 x 5 =5
• Add Exponents
3+2=5
• Answer 5 x 10 5
• A 2 step process
(4 x 103) ÷ (2 x 10-6)
Division:
• Divide Coefficients
4 ÷ 2 =2
• Subtract Exponents
3 – (-6) = 9
• Answer 2 x 10 9
The Mole (Mol)
• This is a number scientists use to count
particles like
– Atoms (Cu)
– Molecules (H20)
– Ionic Compound Formula Units (NaCl)
• 12=Dozen
• Pair=2
• Mol=6.02x1023
– 602, 213, 670, 000,000,000,000,000
Using Molar Mass
• Let us convert between particles, mass, mols.
How did they come up with that
number?
• Used to measure the amount of a substance.
• Based on the amount of atoms in 12 grams of
carbon
• Also called the mol or Avogadro’s number:
– An Italian Scientist who found the volume of 1 mol
of gas.
Using the Mol:
Converting moles to find Particles
• Conversion Factors:
6.02x1023 particles
1 mol
• Particles= (number of moles) x 6.02x1023 particles
1 mol
• How many molecules in 3.5 moles of sucrose?
3.5 mol sucrose x 6.02x1023 particles = 2.1 x 1024 molecules of sucrose
1 mol sucrose
Using the Mol:
Converting particles to find moles
• Conversion Factors:
_____1 mol_____
6.02x1023 particles
• moles= (number of particles) x _____1 mol_____
6.02x1023 particles
• How many moles in 4.5 x 1024 atoms of Zinc?
2.1 x 1024 atoms of Zn x = 1 mol Zn atoms
= 7.5 moles of Zn atoms
6.02x1023 Zn Atoms
Mass and the Mole
• Molar Mass: The Mass of 1 mole of pure
substance.
– This is numerically equal to the atomic mass of a
substance
– 12g of Carbon = 1 mol of Carbon atoms
– 16g of Oxygen= 1 mol of OxygenAtoms
– 32g of O2 = 1 mol of Oxygen Molecules
– How many grams for a mol of CO2?
Mass and the Mole
• Molar Mass: The Mass of 1 mole of pure
substance.
– This is numerically equal to the atomic mass of a
substance
– 12g of Carbon = 1 mol of Carbon atoms
– 16g of Oxygen= 1 mol of OxygenAtoms
– 32g of O2 = 1 mol of Oxygen Molecules
– How many grams for a mol of CO2?
• Add Mass of C + Mass of O + Mass of O
• 12g+16g+16g= 44g