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Help students
develop the skill
of critical thinking.
CRITICAL thinking is the
process of analyzing and
applying what you already
know as a guide to action.
Critical thinking attempts
to intellectually figure
something out.
Qu i ckTi me ™ an d a
de co mp res so r
a re ne ed ed to se e thi s p i ctu re .
Putting names
and faces together.
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The study of
the properties
of materials and
the changes that
materials undergo.
You know the active
ingredient in beer
is C2H5OH.
Instead of saying
ozone, you say O3.
You refer to the smell
of nail polish remover
as an acetone smell.
You ask for
acetaminophen
instead of Tylenol.
When you hear the word
MOLE, you think of the
23
number 6.02 X 10
instead of a small furry animal.
You wash your hands
BEFORE you go
to the bathroom.
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Safety
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What's wrong with this picture?
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Safety glasses should ALWAYS
be worn during a lab.
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Long hair should be
tied back.
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Bulky and loose clothing
Are dangerous in the lab.
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Flammable materials must
be kept away from lab burners.
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You DON'T want to be like this!
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Or this!
Horse-play has
no place in
the lab.
If it occurs, those involved
will be disqualified from
the lab and given a ZERO
for the assignment.
Horse-play has
no place in
the lab.
You probably would
not intentionally
harm someone, BUT
accidents can happen.
Lack of pre-lab
preparation
is the main threat to
safety in our lab.
Lack of pre-lab
preparation
If you are unprepared, you will
be unsure of what to do, waste
time, and have a good chance
of making a mistake that leads
to a problem.
At the beginning
of each lab
Pay close attention to
verbal instructions
given at this time.
At the beginning
of each lab
You will be given a
chance to ask questions
before we begin.
At the beginning
of each lab
THIS is the time to ask...
NOT after the lab starts.
Once the lab starts,
you and your group
are on your own.
I will get involved
only with issues
of SAFETY…
and that will
cost your group
10 POINTS.
Water and acid combine in
an EXOTHERMIC reaction.
Water and acid combine in
an EXOTHERMIC reaction.
Water and acid combine in
an EXOTHERMIC reaction.
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Lab Safety 1 - 16 min
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Lab Safety 2 - 24 min
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Lab Equipment
Lab Equipment
??
Lab Equipment
Erlenmeyer
flask
Lab Equipment
Erlenmeyer flask ??
Lab Equipment
Erlenmeyer flask Beaker
Lab Equipment
Erlenmeyer flask Beaker ??
Lab Equipment
Erlenmeyer flask Beaker Test tube
Lab Equipment
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??
Lab Equipment
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a re n e e d d to s e e th s p i tu re .
Graduated
Read the bottom
Cylinder
of the meniscus.
Lab Equipment
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a re n e e d d to s e e th s p i tu re .
Graduated
Cylinder
??
Read the bottom
of the meniscus.
Lab Equipment
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TIF (Un co m p s s e ) d e co m p s s o
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F re r
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a re n e e d d to s e e th s p i tu re .
Graduated Volumetric
Cylinder
Read the bottom Flask
of the meniscus.
Lab Equipment
??
Lab Equipment
Volumetric
Pipet
Lab Equipment
Volumetric
Pipet
??
Lab Equipment
Volumetric
Pipet
Dropper Pipet
Lab Equipment
Volumetric
Pipet ??
Dropper Pipet
Lab Equipment
Volumetric Mohr
Pipet
Pipet
Dropper Pipet
Lab Equipment
Standard
Pipet
Bulb
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Safety
Pipet
Pipet
Bulb
Lab Equipment
Draw liquid into
the pipet with the
bulb, NEVER by
mouth like a straw.
Lab Equipment
Quickly remove
the standard bulb
and place your
finger over the
top to hold
in the liquid.
Lab Equipment
Roll your finger
SLOWLY to allow
liquid to flow
from the pipet.
This takes
practice!
Lab Equipment
Do not remove the
liquid remaining in
the tip. MOST pipets
are calibrated to
retain this amount.
Lab Equipment
Professional labs
today use "automatic"
pipets with disposable
tips.
Lab Equipment
A buret is a uniform
cylinder designed to
accurately measure
a volume of liquid
transferred to
another vessel.
Lab Equipment
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??
Lab Equipment
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Evaporating
Dish
Lab Equipment
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Evaporating ??
Dish
Lab Equipment
Q uic kT ime ™ a n d a
T IFF (U n co mp r es s ed ) de c om pr e s so r
a re n ee d ed to s ee this pic tu re .
Evaporating Watch
Dish
Glass
Lab Equipment
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a re n ee d ed to s ee this pic tu re .
Evaporating
Watch ??
Glass
Dish
Lab Equipment
Q uic kT ime ™ a n d a
T IFF (U n co mp r es s ed ) de c om pr e s so r
a re n ee d ed to s ee this pic tu re .
Evaporating
Watch Crucible
Glass
Dish and Cover
Lab Equipment
Q uic kT ime ™ a n d a
T IFF (U n co mp r es s ed ) de c om pr e s so r
a re n ee d ed to s ee this pic tu re .
Evaporating
Watch
Glass
Crucible
and Cover
??
Dish
Lab Equipment
Q uic kT ime ™ a n d a
T IFF (U n co mp r es s ed ) de c om pr e s so r
a re n ee d ed to s ee this pic tu re .
Evaporating
Watch Crucible Glass
Glass and Cover
Dish Stirring
Rod
Lab Equipment
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??
Lab Equipment
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Support
Ring
Lab Equipment
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Support ??
Ring
Lab Equipment
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Support Utility
Ring
Clamp
Lab Equipment
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Support Utility
Clamp
??
Ring
Lab Equipment
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a re ne ed ed to se e thi s p i ctu re .
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Support Utility Wire
Ring Clamp
Gauze
Lab Equipment
??
Lab Equipment
Wire
Triangle
Lab Equipment
Wire
Triangle ??
Lab Equipment
Wire Lab
Triangle
Burner
Lab Equipment
Wire Lab
Triangle Burner
??
Lab Equipment
Wire Lab
Triangle Burner
Ring
Stand
Lab Equipment
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are ne eded to see th is pi cture. a re ne ed ed to se e thi s pi ctu re.
??
Lab Equipment
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are ne eded to see th is pi cture. a re ne ed ed to se e thi s pi ctu re.
Lab Equipment
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are ne eded to see th is pi cture. a re ne ed ed to se e thi s pi ctu re.
Crucible
Tongs ??
Lab Equipment
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are ne eded to see th is pi cture. a re ne ed ed to se e thi s pi ctu re.
Crucible Test tube
Tongs
Holder
Lab Equipment
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are ne eded to see th is pi cture. a re ne ed ed to se e thi s pi ctu re.
Crucible
Tongs
Test tube
Holder
??
Lab Equipment
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are ne eded to see th is pi cture. a re ne ed ed to se e thi s pi ctu re.
Crucible Test tube Striker
Tongs Holder
Lab Equipment
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??
Lab Equipment
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Thermometer
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Thermometer
??
Lab Equipment
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Thermometer
Wash
Bottle
Lab Equipment
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Thermometer Wash
Bottle
??
Lab Equipment
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Thermometer Wash Chemical Spoon
Bottle
or Spatula
Lab Equipment
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a re n ee d ed to s e e th is p ic tur e .
??
Lab Equipment
1
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Filter paper
Q uic kT im e™ an d a
Fold filter paper
T IFF ( Un c om pr e s se d ) d e co m pr e ss o r
a re n ee d ed to s e e th is p ic tur e .
in half - twice -
to make a cone
for the funnel.
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Filter
4
Funnel 3 open edges on one side,
1 open edge on the other.
Lab Equipment
Support the funnel
with a ring stand.
NEVER allow the
sample to go over
the top of the
filter paper.
Lab Equipment
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Electronic Triple-beam
Balance Balance
NEVER place chemicals
directly on the balance pan!
The Bunsen Burner
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Attach the burner hose to
the nozzle and turn on the
gas at the wall FIRST.
The gas is fully on
when the handle
is PARALLEL with
the nozzle.
Attach the burner hose to
the nozzle and turn on the
gas at the wall FIRST.
Always use the
burner with
the nozzle in
this position.
Attach the burner hose to
the nozzle and turn on the
gas at the wall FIRST.
Move the handle
all the way in
either direction
to turn it off.
When you HEAR
gas coming out
of the burner,
start the flame and a
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The hottest part of the flame
is at the top
of the inner
cone. QuickTime™ and a
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If there is only ONE flame,
open the air vent at the
bottom of the burner.
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Clean-up is important for the
safety of those that come after
you AND for the preservation
of lab equipment.
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Clean-up will vary from lab
to lab. Instructions will be
given for appropriate clean-up
for each lab.
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NEVER put
broken glass
in the trash can.
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Some chemicals can be put
down the drain - with LOTS
of running water...
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Other chemicals must be
put in a waste container -
AS DIRECTED.
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NEVER put
un-used chemicals
back into their
original container.
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ALWAYS read the
labels on containers.
National Fire Protection Association
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National Fire Protection Association
OSHA Approved Signs
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Major safety A hazard
hazard to safety
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Possible Safety
hazard information
MSDS
Material Safety Data Sheet
Provides all relevant safety
information about a chemical
Separating a Mixture
Chemistry is
NOT a math
class, but you
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OWN scientific
calculator.
ALL Measurements in Science
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use the
Metric System -
.eru tcip sih t ee s o t d edeen e ra
ros serpmoced )de sserpmoc nU ( F FI T
a dna ™emi Tk ciu Q
The International System
NOT the
English System QuickTime™ and a
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Measurement - 21 min
SI Base Units
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Mass kilogram
Length meter
Time second
Energy Joule
Temperature Celsius o
Amount of substance mole
Derived Units
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Derived units involve
multiple base units.
Derived Units
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Area = length 2
Derived Units
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Area = length 2
Volume = length 3
Derived Units
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Area = length 2
Volume = length 3
Density = mass / volume
Important Derived Units
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1 liter = 1 cubic decimeter, dm3
Important Derived Units
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1 liter = 1 cubic decimeter, dm3
1 milliliter = 1 cubic centimeter, cm3
Important Derived Units
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1 liter = 1 cubic decimeter, dm3
1 milliliter = 1 cubic centimeter, cm3
Density of H2O = 1 gram / cm3
"cubic centimeters" NOT centimeters cubed
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kilo = 1000
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hecto = 100
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deca = 10 QuickTime™ and a
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the base = 1
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deci = 0.1
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centi = 0.01
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milli = 0.001
When converting from a
big prefix to a small prefix...
kilo hecto deka 1 deci centi milli
multiply by 10 with each step.
When converting from a
big prefix to a small prefix...
X10
kilo hecto deka 1 deci centi milli
1 dekameter = 10 meters
When converting from a
big prefix to a small prefix...
X10
kilo hecto deka 1 deci centi milli
1 dekameter = 10 meters
1 dekameter = ? centimeters
When converting from a
big prefix to a small prefix...
X10
kilo hecto deka 1 deci centi milli
1 dekameter = 10 meters
1 dekameter = 1000 centimeters
When converting from a
small prefix to a big prefix...
/10
kilo hecto deka 1 deci centi milli
divide by 10 with each step.
When converting from a
small prefix to a big prefix...
/10
kilo hecto deka 1 deci centi milli
1 centimeter = .01 meters
When converting from a
small prefix to a big prefix...
/10
kilo hecto deka 1 deci centi milli
1 centimeter = .01 meters
1 centimeter = ? kilometers
When converting from a
small prefix to a big prefix...
/10
kilo hecto deka 1 deci centi milli
1 centimeter = .01 meters
1 centimeter = .00001 kilometers
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cm 3
All numbers in chemistry
are measurements -
so they MUST have units.
oC F
TIF (Un co m p s s e ) d e co m p s s o
c
Qu i k Ti me ™ a d a
re d
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g
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a re n e e d d to s e e t i s p i tu re.
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There are always
limitations in the
measuring equipment
and in the
ability of the
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the equipment.
Measured quantities
are properly reported
in such a way that
only the last digit
is uncertain.
All digits of a measured
quantity, including
the uncertain one,
are called
significant figures.
The greater the number
of significant figures,
the greater the
implied certainty of
the measurement.
This scale
can report
only 2
significant
figures.
The first
measured #
is certainly 2.
The second #
must be
estimated.
105
The reading
could be
reported as
28 or 29...
But it could not
be reported as
28.5
A reading of 28.5
implies that ones
were measured
and tenths
estimated.
Important
When a calculation involves
measurements with different
numbers of significant figures,
the answer should have the
same number of significant
figures as the LEAST in the
measurements.
Important
length X width X height = volume
2 cm X 5.5 cm X 2.258 cm =
24.838 cm3
Can we REALLY know the volume to
thousandths of a cubic centimeter?
Important
length X width X height = volume
2 cm X 5.5 cm X 2.258 cm =
24.838 cm3
What should be the answer?
Important
length X width X height = volume
2 cm X 5.5 cm X 2.258 cm =
24 or 25 cm3
20 cm 3
Rules for assigning significance
1. Digits other than zero
are always significant.
Rules for assigning significance
1. Digits other than zero
are always significant.
6 ml
6.6 ml
66.24 ml
Rules for assigning significance
1. Digits other than zero
are always significant.
6 ml 1
6.6 ml 2
66.24 ml 4
Rules for assigning significance
2. Rules for zeros:
Rules for assigning significance
2a. A single zero BEFORE
the decimal point
is NEVER significant.
Rules for assigning significance
2a. A single zero BEFORE
the decimal point
is NEVER significant.
0.6 ml
Rules for assigning significance
2a. A single zero BEFORE
the decimal point
is NEVER significant.
0.6 ml 1
Rules for assigning significance
2b. Final zeros AFTER
a decimal point are
always significant.
Rules for assigning significance
2b. Final zeros AFTER
a decimal point are
always significant.
0.6 ml
6.0 ml
6.60 ml
Rules for assigning significance
2b. Final zeros AFTER
a decimal point are
always significant.
0.6 ml 1
6.0 ml 2
6.60 ml 3
Rules for assigning significance
2c. Zeros BETWEEN two
significant figures are
always significant.
Rules for assigning significance
2c. Zeros BETWEEN two
significant figures are
always significant.
6006 ml
6.02 g
0.600 kg
Rules for assigning significance
2c. Zeros BETWEEN two
significant figures are
always significant.
6006 ml 4
6.02 g 3
0.600 kg 3
Rules for assigning significance
2d. Zeros used ONLY to
space the decimal are
never significant.
Rules for assigning significance
2d. Zeros used ONLY to
space the decimal are
never significant.
100 g
0.001 ml
0.000602 ml
Rules for assigning significance
2d. Zeros used ONLY to
space the decimal are
never significant.
100 g 1
0.001 ml 1
0.000602 m 3
Rules for assigning significance
2e. Scientific notation
23
6.02 X 10 atoms
Rules for assigning significance
2e. Scientific notation
23
6.02 X 10 atoms
Any digits BEFORE the X
are always significant.
Rules for assigning significance
2e. Scientific notation
23
6.02 X 10 atoms
The powers of 10
are never significant.
One last hint about
significant figures:
Accepted equalities,
like 1 foot equals 12 inches,
are considered to have an
INFINATE number of
significant figures.
Important
You will probably be required
to used significant figures in
college chemistry class when
rounding off calculations.
Important
HHS chemistry class places
more importance on using
the OVERALL PROCESS
than the minute details.....
Important
You may round off final
answers liberally in this class...
as long as you show the
process by which you
GOT the answer.
Bring your
calculator
QuickTime™ and a
to class.
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Experimental error is a
comparison of a value obtained
by measurement to an
accepted theoretical value.
The accepted theoretical
value is either obtained
from reference material
or calculated.
experimental _ theoretical
value value
% error = X 100
theoretical value
Exp Error Practice Problem.
A student determines experimentally
that the density of water is
0.85 grams per cubic centimeter.
Calculate the student's
experimental error.
_
0.85 g 1.00 g
% error = X 100
1.00 g
% error = 15 %
Exp Error Practice Problem.
Before drying, a sample weighs 5.6 g.
After drying, it weighs 4.2 g.
The sample is known to contain
3.0 grams of water.
Calculate the experimental error.
% error = 53 %
_
1.4 g 3.0 g
% error = X 100
3.0 g
Using
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calculator.
Problem #1:
(10.25) (5.74 X 10 4) =
give the answer in
scientific notation
Problem #1:
(10.25) (5.74 X 10 4) =
588350
Problem #1:
(10.25) (5.74 X 10 4) =
588350
significant figures?
Problem #1:
(10.25) (5.74 X 10 4) =
5.88 X 105
Problem #2:
(6.2 X 10-12) (3.87 X 109) =
give the answer in
scientific notation
Problem #2:
(6.2 X 10-12) (3.87 X 10 9) =
0.023994
significant figures?
Problem #2:
(6.2 X 10-12) (3.87 X 10 9) =
2.4 X 10-2
Problem #3:
(6.02 X 1023) (1.05 X 1012) =
6.32 X 1035
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Dimensional Analysis -
the most important math
in all of chemistry!!
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Dimensional Analysis -
used to convert from one
type of unit to another.
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Dimensional Analysis -
treats numbers and
units equally.
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First -
write what is given.
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Then -
multiply by fractions
equal to 1 to change
the units.
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When -
the only units NOT canceled
are the units asked for,
the problem is worked.
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A problem:
How many cups of oil
are in a barrel of oil?
Known equalities:
1 barrel = 42 gallons
1 gallon = 4 quarts
1 quart = 4 cups
Step 1: write what is given.
1 barrel
Step 1: write what is given.
1 barrel
Step 1: write what is given.
1 barrel
This line means divide by.
Step 1: write what is given.
1 barrel
This line means multiply by.
Step 2: multiply by fractions
equal to one.
1 barrel
Step 2: multiply by fractions
equal to one.
1 barrel
What units
go here?
Step 2: multiply by fractions
equal to one.
1 barrel
barrels
Now we'll be able to
cancel barrels.
Step 2: multiply by fractions
equal to one.
What units
1 barrel go here?
barrels
Step 2: multiply by fractions
equal to one.
1 barrel gallons
barrels
Step 2: multiply by fractions
equal to one.
1 barrel gallons
barrels
What numbers will make
this fraction equal to 1?
Step 2: multiply by fractions
equal to one.
1 barrel 42 gallons
1 barrels
Step 2: multiply by fractions
equal to one.
1 barrel 42 gallons
1 barrels
Barrels have been
converted to gallons.
Step 2: multiply by fractions
equal to one.
1 barrel 42 gallons
1 barrels
What units go here?
Step 2: multiply by fractions
equal to one.
1 barrel 42 gallons
1 barrels gallons
Step 2: multiply by fractions
equal to one.
1 barrel 42 gallons
1 barrels gallons
What units go here?
Step 2: multiply by fractions
equal to one.
1 barrel 42 gallons quarts
1 barrels gallons
Step 2: multiply by fractions
equal to one.
1 barrel 42 gallons quarts
1 barrels gallons
And the numbers are?
Step 2: multiply by fractions
equal to one.
1 barrel 42 gallons 4 quarts
1 barrels 1 gallon
Step 2: multiply by fractions
equal to one.
1 barrel 42 gallons 4 quarts
1 barrels 1 gallon
Gallons have become quarts.
Step 2: multiply by fractions
equal to one.
1 barrel 42 gallons 4 quarts
1 barrels 1 gallon
Are we done yet?
Step 2: multiply by fractions
equal to one.
42 gallons 4 quarts
1 barrel
1 barrels 1 gallon
What units go here?
Step 2: multiply by fractions
equal to one.
42 gallons 4 quarts
1 barrel
1 barrels 1 gallon quarts
Step 2: multiply by fractions
equal to one.
42 gallons 4 quarts
1 barrel
1 barrels 1 gallon quarts
And here?
Step 2: multiply by fractions
equal to one.
42 gallons 4 quarts cups
1 barrel
1 barrels 1 gallon quarts
Step 2: multiply by fractions
equal to one.
42 gallons 4 quarts cups
1 barrel
1 barrels 1 gallon quarts
And the numbers are?
Step 2: multiply by fractions
equal to one.
42 gallons 4 quarts 4 cups
1 barrel
1 barrels 1 gallon 1 quart
Quarts have become cups.
Step 2: multiply by fractions
equal to one.
42 gallons 4 quarts 4 cups
1 barrel
1 barrels 1 gallon 1 quart
Have we worked the problem?
Step 2: multiply by fractions
equal to one.
42 gallons 4 quarts 4 cups
1 barrel
1 barrels 1 gallon 1 quart
All units have been canceled
except those we are looking for.
Step 3: DO THE MATH.
42 gallons 4 quarts 4 cups
1 barrel
1 barrels 1 gallon 1 quart
We are ready to punch
the buttons on the calculator.
Step 3: DO THE MATH.
42 gallons 4 quarts 4 cups
1 barrel
1 barrels 1 gallon 1 quart
1 barrel = 672 cups
Another problem:
A music CD costs 12 dollars.
There are 16 songs on the
CD. How many cents does
each song cost?
What are we given:
A music CD costs 12 dollars.
There are 16 songs on the
CD. How many cents does
each song cost?
What are we asked for:
What are we given:
COST PER CD
A music CD costs 12 dollars.
There are 16 songs on the
CD. How many cents does
each song cost?
What are we asked for:
COST PER SONG
Write what is given:
12 dollars
CD
Multiply by fractions equal to 1:
12 dollars
CD
What do we want
to cancel?
Multiply by fractions equal to 1:
12 dollars
CD
Where does it go?
Multiply by fractions equal to 1:
12 dollars CD
CD
Multiply by fractions equal to 1:
12 dollars CD
CD
What goes here?
Multiply by fractions equal to 1:
12 dollars CD
CD songs
Multiply by fractions equal to 1:
12 dollars CD
CD songs
And the numbers are?
Multiply by fractions equal to 1:
12 dollars 1 CD
CD 16 songs
Multiply by fractions equal to 1:
12 dollars 1 CD
CD 16 songs
What are our units?
Multiply by fractions equal to 1:
12 dollars 1 CD
CD 16 songs
dollars per song
Multiply by fractions equal to 1:
12 dollars 1 CD
CD 16 songs
What goes here?
Multiply by fractions equal to 1:
12 dollars 1 CD
CD 16 songs dollars
Multiply by fractions equal to 1:
12 dollars 1 CD
CD 16 songs dollars
And here?
Multiply by fractions equal to 1:
cents
12 dollars 1 CD
CD 16 songs dollars
Multiply by fractions equal to 1:
cents
12 dollars 1 CD
CD 16 songs dollars
And the numbers are?
Multiply by fractions equal to 1:
100 cents
12 dollars 1 CD
CD 16 songs 1 dollar
Multiply by fractions equal to 1:
100 cents
12 dollars 1 CD
CD 16 songs 1 dollar
What are our units?
DO THE MATH:
100 cents
12 dollars 1 CD
CD 16 songs 1 dollar
cents per song
DO THE MATH:
100 cents
12 dollars 1 CD
CD 16 songs 1 dollar
75 cents / song
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Chemistry - 44 min
