6.02 X 1023
THE MOLE
Relating Mass to Numbers of Atoms
THE MOLE
 In
chemistry, the __________ is the
"name for a number," and that's all!
 602,200,000,000,000,000,000,000 or
______________
 Used to talk about extremely __________
numbers of extremely __________ objects,
such as molecules, __________ or
electrons.
 This is called Avogadro’s Number.
AVOGADRO’S NUMBER
 _______________
was an Italian scientist who
explained the relationship between ________
and ____________ of atoms.
 12.0 g of carbon-12 contains 6.022 1367 x 1023
carbon-12 atoms.
 Avogadro’s number is _________________ to
6.02 x 1023
 This is the number of ___________ in ______
mole.
 So, ________ mole = 6.02 x 1023
MOLAR MASS


The mass of one mole of a ________ substance
Units = __g_
mol
Molar mass of an element = ____________ _______
of the element.
Molar mass of
Al = ________________
Li = ________________
He = _______________
LAW OF CONSERVATION OF MASS
 Mass
is neither ___________________ nor
_____________________ during ordinary
__________________ or ______________
changes.
MOLAR MASS OF COMPOUNDS

A compounds ___________ mass is numerically =
to its __________________ mass.
H2O
2 mol H x 1.01 g H = 2.02 g H
1 mol H
1 mol O x 16.00 g O = 16.00 g O
1 mol O
Formula mass of H2O = ___________ amu
__________ __________of H20 = 18.02 g/mol
MOLAR MASS EXAMPLE
What is the molar mass of K2SO4?
__ mol K x 39.10 g K = ______________
1 mol K
__ mol S x 32.10 g S = ______________
1 mol S
__ mol O x 16.00 g O = ______________
1 mol O
__________ _______K2SO4 = ___________
How many moles of each element are present in this compound?
2 mol K, 1 mol S, 4 mol O
MOLAR CONVERSION EXAMPLES

How many moles of carbon are in 26 g of carbon?
26 g x 1 mol = ______________
12 g
How many atoms are there in 1.50 mol Na?
1.50 mol Na x 6.02 x 1023 = _______________
What is the mass in grams of 6.50 mol Cu?
6.50 mol Cu x 63.5 amu =
_______________

MORE MOLAR CONVERSION EXAMPLES
What is the mass in grams of 6.25 moles copper (II) nitrate?
Cu 2+ NO3 - : formula is
Cu(NO3)2
Find molar mass of Cu(NO3)2 first.
1 mol Cu x 63.55 g Cu = ________________
1 mol Cu
2 mol N x 14.01 g N = __________________
1 mol N
6 mol O x 16.00 g O = __________________
1 mol O
molar mass Cu(NO3)2 = _______________
Now find mass in grams of 6.25 moles:
6.25 moles x 187.57 g = 1172 g
Ans. ______________
1 mol