The document discusses the mole concept in chemistry. It defines a mole as 6.022x1023 particles of an element or compound. It explains that the mass of one mole of a substance is equal to its molecular mass in grams. Different substances have different molecular masses, so one mole of one element will weigh more or less than one mole of another element. The document also discusses how balanced chemical equations show equal numbers of moles on each side and how moles can be used to calculate mass by multiplying the number of moles by the molecular weight.

1. MEASURING
MOLES

2. Menu
 The mole concept
 The mass of moles
 Stoichiometry
 Conversion calculations

3. What is a mole?
 A pair is two of something
 A dozen is 12 of something
 A gross is 144 of something
 A mole is 6.022x1023 of
something

4. How much do moles weigh?
 Weight of one mole = molecular mass in
grams
 Different substances have different
molecular mass.
 Weight of one mole of Neon = weight of
about 5 moles of Helium

5. What is a balanced equation?
 The moles of each element must be equal on
both sides
SnO2 + 2 H2 → Sn + 2 H2O
1 mole Sn 1 mole Sn
2 moles O 2 moles O
4 moles H 4 moles H

6. How can I calculate mass?
 Use the number of moles to calculate mass.
 Multiply the number of moles by the molecular
weight.
12.01 g 30.03 g
One mole of Carbon 2.5 moles of Carbon