Transcript A Mole is Many Things

A Mole is Many
Things
How do you measure matter?
Measuring by mass….


Potatoes are measured by the pound.
Gold is measured by the ounce.
Measuring by volume….



Apples are measured by the bushel.
Soda is measured by the liter.
Gasoline is measured by the gallon.
How do you measure matter?
Some items are measured by
counting how many you have.


Eggs are measured by the dozen.
Pencils are measured by the gross.
The “chemical counting unit”
is the mole.


The mole is the SI unit for amount of
substance.
The particles of a substance could be
atoms, molecules, or ions, which are very
small.
 Just
as a dozen eggs represents
12 eggs, a mole (mol) represents
6.02 x 1023 representative
particles of a substance.
 This
number is called Avogadro’s
number, in honor of Amedeo
Avogadro, and it is a very large
number.
The Mole
 Avogadro’s
number is
6.02 x 1023.
A
mole is
6.02 x 1023
particles of a
substance.
How big is a mole?
 602000000000000000000000
particles, which is…

602,000 x 1 million x 1 million x 1 million
 If
you had a mole of
watermelon seeds, you
would have a melon slightly
larger than the moon.
A
mole of donut holes would
cover the earth and be 5
miles deep.
 If
you had a mole of
pennies and stacked them
up, the stack would 7 times
the distance from the Earth
to the moon.



A mole of rice grains would cover the land
area of the Earth to a depth of about 75
meters.
A mole of rice grains is more grains than
all the grain that has been grown since
the beginning of time.
A mole of rice would occupy a cube about
120 miles on each edge.
 Assuming
that each human has
60 trillion body cells (6 x 1013)
and the Earth’s population is over
6.7 billion (6.7 x 109), the total
number of living human body
cells on the Earth at the present
time is 4.02 x 1023, or only 2/3 of
a mole.


If one mole of pennies were divided up
among the Earth’s population, each
person would receive 9 x 1013 pennies.
Personal spending at the rate of one
million dollars a day would use up each
person’s wealth in 2500 years.
Life would not be comfortable because the
surface of the Earth would be covered in
copper coins to a depth of at least 400
meters.
A representative particle is…
 The
smallest unit into which a
substance can be broken down
without a change in composition.
 The
representative particle of
most elements is the atom.
Substance


Representative particle
Element
Diatomic element
Atom
Molecule
(Br2, I2, N2, Cl2, H2, O2, F2)


Molecular compound
Ionic compound
Molecule
Formula Unit
 Remember:
A
formula unit is the lowest whole
number ratio of ions in an ionic
compound.
Mole-Particle Conversion Practice
Mole Samples
If a carbon atom has an atomic mass of
12.01 amu and a hydrogen atom has an
atomic mass of 1.008 amu, we could say
one carbon atom is about 12 times as
massive as one hydrogen atom.


Would 100 carbon atoms be about 12
times as massive as 100 hydrogen atoms?
Would 1 mole of carbon atoms be about
12 times as massive as 1 mole of
hydrogen atoms?

Scientists define the mole as the amount
of substance that contains as many
particles (atoms, molecules, of formula
units) as there are atoms in exactly 12
grams of the carbon-12 isotope.
Molar Mass…
is the mass of a mole of a substance.
Gram atomic mass is the mass of a mole of
atoms.
Gram molecular mass is the mass of a mole
of molecules.
Gram formula mass is the mass of a mole of
a substance.
Molar Mass

What is the gram atomic mass of zinc?

What is the gram molecular mass of CO2?

What is the gram formula mass of NaCl?

What is the molar mass of titanium?




Mole Fact References:
Professor Mole, Quality Science & Software, Inc.
Doris Kolb. “The Mole,” J. Chem. Educ.
Reactions and Reason, Heikkinan and Atkinson