Notes The Mole

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Transcript Notes The Mole

The MOLE
What is a mole?
It is not…

A Furry Little
Animal that cannot
see…
OR a raised dark
mark on a person…
It a word that means a number, just
like…
1
1
1
1
1
1
pair = 2 objects
dozen = 12 objects
score = 20 objects
gross = 144 objects
ream = 500 objects
mole = 6.02 x 1023 objects
MOLE
 Is
a unit developed to help count
particles since they are so small
 1 mole = 6.02 x 1023 particles
 That’s 602,000,000,000,000,000,000,000
 Particle
or ions
– can be atoms, molecules,
ALSO CALLED AVOGADRO’S NUMBER!
Atomic Mass
 The
mass of one atom (in units of
amu)
 It is the mass number found on the
periodic table rounded to ONE
decimal place (in units of amu)
 Ex:
Carbon 12.0 amu
Neon 20.2 amu
Formula Mass
 The
sum of all the atomic masses (in
amu) of the atoms in a compound
 Ex: H2O
1.0 + 1.0 + 16.0 = 18.0 amu
 Ex:
C12H22O11
12(12.0) + 22(1.0) + 11(16.0) =
342.0 amu
Molar Mass
 The
mass (in units of grams) of 1
mole of a substance
OR
 The mass (in units of grams) of 6.02
x 1023 particles of a substance
OR
 The mass number on the periodic
table rounded to one decimal place
(in units of grams)
Formula Mass Vs Molar Mass
The value of FMs and MMs will be
the same, the difference is the
unit…


Formula mass for
HCl is…
1.0+35.5=36.5 amu

This is the mass of
1 MOLECULE of HCl

Molar mass for HCl
is…
1.0+35.5=36.5 g
This is the mass of
1 MOLE (6.02x1023)
of molecules of HCl
More Practice…
 What
is the formula mass for C2H4?
2(12.0) + 4(1.0) = 28.0 amu
 What is the molar mass for C2H4?
2(12.0) + 4(1.0) = 28.0 g
 What is the formula mass for C2H5Cl?
2(12.0) + 5(1.0) + 35.5 = 64.5 amu
 What is the molar mass for C2H5Cl?
2(12.0) + 5(1.0) + 35.5 = 64.5 g