6.022 x 1023 Representative Particles
per ????
Equivalent to covering the continental U S
Nine Miles deep with popcorn kernels.
(unpopped!)
Gram Formula Mass
Gram Moles of NaCl, CaCl2?
Molar Mass of any substance is the mass of
one mole of substance.
How many grams are in 9.45 moles of Dinitrogen
Trioxide?
What is the formula for Dinitrogen Trioxide?
N2O3
Convert Moles to Grams
1 gram mole of N2O3 = 2(14.007) + 3(15.999)
= 28.014 + 47.997
= 76.011 g N2O3
mole N2O3
9.45 mole N2O3| 76.011 g N2O3 = 718 g N2O3
|mole N2O3


Find the number of moles of Iron (III) Oxide,
Fe2O3 , when you have 92.2 g of Fe2O3?
You want to convert Grams  Moles






Fe = 55.845 O = 15.999
2(55.845) + 3(15.999) = 159.69 g
Gram Formula Mass of Fe2O3 is 159.69 g Fe2O3
mole Fe2O3
Using Dimensional Analysis to set up calculation:
92.2 g Fe2O3 | mole Fe2O3 = 0.577 mole Fe2O3
|159.69 g Fe2O3
Given 46.25 g of Pb how many atoms are
present?
46.25 g Pb | 1mole Pb | 6.022 x 1023 atoms Pb =
| 207.2 g Pb| 1 mole Pb
=
23
22
1.334
x10
x 10 atoms Pb
Atoms Pb
Given 9.345 x 1021 molecules of NaNO3 how
many grams are present?
9.345 x 1021 molecules NaNO3 |
1 mole NaNO3
|
6.022 x 1023
| molecules NaNO3
| 84.994 g NaNO3=
|
|
= 1.319 g NaNO3

Volumes of different 1 mole quantities of
solids and liquids not the same.

Differences due to properties of solids &
liquids.

Volume of 1 mole of gas much more
predictable under same physical conditions.
The volume of a gas changes with variation in
Temperature and Pressure .
Because of this variation, the volume of gas
measured is referenced to a Standard Temperature
and Pressure (STP).
STP
Temperature = 0 C
Pressure = 1.00 Atm = 760 torr
= 760 mm Hg =101.3 kPa
22.4 Liters of any gas @ STP contains
6.022 x 1023 representative particles
(usually atoms or molecules, rarely formula
units).
22.4 Liters is known as the Molar Volume


Would 22.4 liters of one gas have the same
mass of 22.4 liters of a different gas???
Gram molar mass of different compounds
determines mass
Mole Map
molecules,
formula
units
# of atoms
molecule
molecule
#atoms
# of
atoms
6.022 x 1023
1 mole
1 mole____
6.022 x 1023
mole
formula mass Mass in
1 mole
1 mole____ grams
formula mass
22.4 L
1 mole
1 mole
22.4 L
Volume
@ STP
Find volume in liters of 0.60 mol of SO2 at STP…
Convert moles to liters
0.60 mole SO2| 22.4 Liters SO2 =
|1 mole SO2
13.4 Liters SO2
How many moles of SO2 in 67.2 L of SO2 @ STP?
Convert liters to moles
67.2 L SO2| 1 mol SO2 = 3.00 moles SO2
|22.4 L SO2
Density of Gas measured in units of grams
per liter (g/L).
Density of gas @ STP used to calculate molar
mass of gas.
The density of gas in balloon determines if
balloon floats or sinks.
What is density of Krypton gas @ STP?
83.8 g Kr |1mole = 3.74 g Kr
1 mole
| 22.4 L
L

What is STP???
Density of gas containing carbon and oxygen is
1.964 g/L @ STP, find molar mass of compound.
1.964g/L | 22.4 L = 43.99 or 44.0 g
| mole
mole
Is the compound CO or CO2?
CO = 12.011 + 15.999 = 28.010 g/mole
CO2 = 12.011 + 2(15.999) = 44.0 09 g/mole
Now you know how to work with moles in
terms of particles, mass, and volume of gases
@ STP…
To convert from one to the other, MOLE is the
center of conversion!