The document defines a mole as a unit of measurement used in chemistry to represent very small numbers of particles. A mole is equal to 6.022 x 1023 representative particles, whether atoms, molecules, ions or other units. Examples show that 1 mole of an element equals its atomic mass in grams, and 1 mole of a compound equals its molar mass in grams. Common mole conversions involve changing between mass, moles, number of particles, and volume of gases.

1. The Mole
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B.Tech

2. What is a mole?
 A unit of measurement
 Since the numbers in chemistry are so small,
we use a “preferred unit of measurement”
(mole) to represent the small number

3. What are the units of measurement?
 "that equal number" of atoms arbitrarily chosen.
 the number of atoms in the atomic weight in g of any
element.
 the number of atoms in 16 g of oxygen, in 4 grams
of He, in 32 g of sulfur, etc.
 the number of molecules in the molecular weight, in
grams, of any compound.
 the number of molecules in 18 g of water, in 40 g of
lithium carbide.
 Much later, a mole, that equal number, was found to
be 6.022 x 1023(representative particles).

4. Examples
 1 mole (or abbr. mol) = 12.011 g of Carbon
 1 mol of Carbon = 6.02 x 1023 atoms of C
 1 mol of H2O = 6.02 x 1023 molecules of
water
 1 mol of NaCl = 6.02 x 1023 units of NaCl

5. Moles in mass
 1 mole can equal the atomic weight of an
element.
 1mol of C = 12.011g of C
 1 mole can equal the atomic weight of a
compound
 1mol of CO = 12.011g of C + 15.99 g of O
= 28.0 g of CO

6. Group Whiteboards
 How many grams are in 1 mol of
 Nitrogen?
 Dinitrogen monoxide?
**How many mols are in 100g sample of N2O?

7. Warm Up #8
 How many grams of Cu are in 1.20 mol of
Cu?
 How many moles are in 70g of Cl?

8. Moles in compounds
Let’s say you have water H2O
How many moles of Hydrogen atoms(ions) are
in water?
 Ask yourself how many individual atoms of
Hydrogen do you see in water?
 Did you say 2???
 Is that your final answer?
 You are correct! So how many mols of
Oxygen atoms do you see?

9. Moles in an equation
2 H2 + O2  2H2O
How many moles of Hydrogen molecules are in
the reactants?
*Coefficients serve as the number of moles too!
Therefore, there are 2 mols of Hydrogen gas

10. Number of
Fundamental
particles
Mass of
substance
Number of
moles
Volume
occupied by
gas at STP
Multiplied by
Avogadro’s Number
Divided by Avogadro’s
Number
Divided by
molar mass
Multiplied by
molar mass
Multiplied by
22.4 dm3
Divided by
22.4dm3

11. Mole Conversions
 Mass to mole or vice versa:
 How many moles are in 24 g of Carbon?
 Look at the solution:
 Start with the given: 24 g (mass) of C
 What do you want in the end? Moles of C
 Use the conversion factor given:
 1 mole
Atomic mass
24 g of C x 1 mol of C = 2.0 mol of Carbon
12.011 g of C

12. Brain Teaser
 Given 200 g of water, how many molecules of
water do you have?
 How many liters of carbon dioxide are in 1.5 x
10^33 molecules of carbon dioxide?

13. More conversion
 Mole to particles or vice versa
 How many atoms are in 2.00 mols of Carbon?
 Look at the boomerang:
 Where do you begin? (the given: mols)
 What do you need in the end? (atoms: particles)
 What’s the conversion factor?
 6.02 x 1023 Atoms of C
1 Mols of C
2.00 mols of C x 6.02 x 1023 atoms of C = 1.20 x 1024 atoms C
1 mol of C

14.  How many molecules of oxygen gas are in
3.0 mols of Oxygen gas?
 How many mols of Oxygen gas are in
4.67 x 1024 molecules of Oxygen gas?
Test Yourself!!!!!!!

15. Final conversion!!!
 Mole to moles of atoms or vice versa
 If you have 2.00 mols of water, how many
moles of hydrogen atoms are there?
 Look at the boomerang:
 Mols  mols of atoms(ions) CF: mols of H+ atoms
mols of water
2.00 mols of H2O x 2 mols of H+ atoms =
1 mol of H2O
= 4.00 mols of H+ atoms

16. Final conversion!!!
 Mole to Volume (gas) or vice versa
 Any gas at STP (standard temperature and
pressure) has a volume of 22.4L per mole
 Look at the cloud chart:
 Mols  volume of gas CF: Moles of gas
22.4L of gas
Ex. How much volume of gas is in 5.00 moles of H2?
5.00 moles H2 x 22.4 L of H2 = 122 L of H2
1 mole of H2