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Chemistry is the study of matter
and the transformations it can
undergo…
Evaluation
The Six Levels
of Thought
Synthesis
“Success is a journey, not a destination.”
-Ben Sweetland
Analysis
Application
Comprehension
Knowledge
“Successful students make mistakes,
but they don’t quit. They learn from them.”
-Ralph Burns
“Success consist of a series of
little daily efforts.”
-Marie McCuillough
Basic Safety Rules
Use common sense.
No unauthorized experiments.
No horseplay.
Handle chemicals/glassware with respect.
Safety Features of the Lab
safety shower
fire blanket
fire extinguisher
eye wash
fume hood
circuit breaker switch
Government
Regulation
worker
OSHA
environment
EPA
The government
regulates chemicals
to protect the…
FDA
USDA
FAA
CPSC consumer
Chemical Exposure
acute exposure
a one-time
exposure
causes damage
chronic exposure
damage occurs
after repeated
exposure
Toxicity
Which is more toxic?
Chemical A: LD50 = 3.2 mg/kg
Chemical B: LD50 = 48 mg/kg
Chemical A is more toxic because less of it
proves fatal to half of a given population.
The Functions of Science
pure science
applied science
the search for
knowledge; facts
using knowledge
in a practical way
?
Pure Science
The search for facts about the natural
world.
- In science, we often try to establish a cause-effect
relationship.
- Driven by curiosity: the need to know, explore,
conquer something new.
Fundamental Properties of Models
A model does not equal reality.
Models are oversimplifications, and are
therefore often wrong.
Models become more complicated as they
age.
We must understand the underlying
assumptions in a model so that we don’t
misuse it.
Using the scientific method requires
that one be a good observer.
observation
uses the five
senses
inference
involves a judgment
or assumption
Data
Observations are also called data.
There are two types of data.
qualitative data
quantitative data
descriptions;
no numbers
measurements;
must have numbers
and UNITS
Parts of the Scientific Method
• Identify an unknown.
• Make a hypothesis
(a testable prediction).
• Experiment to test
the hypothesis.
• Draw a valid conclusion.
A Scientific Experiment
procedure
the order of events
in an experiment;
the “recipe”
variable
any factor that
could influence
the result
Experiments must be controlled; they
must have two set-ups that must differ
by only one variable.
The conclusion must be based on the data.
Scientific Method
•
•
•
•
Observations
Hypothesis
Experimentation
– Controlled (one variable changed at a time)
– Collect data (quantitative and qualitative)
– Analyze data (graph, statistics…trends)
Form valid conclusion.
•
After many experiments…form a theory.
Fundamental Properties of Models
A model does not equal reality.
Models are oversimplifications, and
are therefore often wrong.
Models become more complicated
as they age.
We must understand the underlying
assumptions in a model so that we
don’t misuse it.
Scientific Law vs.
Scientific Theory
A law states what happens.
Law of Gravity
A theory tries to explain why
or how something happens.
Theory of Gravity
Atomic Theory
Collision Theory of Reactions
Experiments
• Law
– A verbal or mathematical description of a
phenomenon that allows for general predictions
– Describes what happens and not why
– Unlikely to change greatly over time unless a major
experimental error is discovered
• Theory
–
Attempts to explain why nature behaves as it does
– Is incomplete and imperfect, evolving with time to explain
new facts as they are discovered
Copyright 2007 Pearson Benjamin Cummings. All rights reserved.
Make observation
Scientific
Method
Ask question
Develop
hypothesis
Test hypothesis
with further
experiments
Test hypothesis
with an
experiment
Revise
hypothesis
Analyze data
and draw
conclusions
Hypothesis
IS
supported
Wysession, Frank, Yancopoulos,
Physical Science Concepts in Action, 2004, page 8
Hypothesis
is NOT
supported
Develop
theory
First
Question
What does the scientist want
to learn more about?
Then
Research
Scientific Method
Gathering of information
Next
An Overview
Hypothesis
An “Educated” guess of an
answer to the question
Then
Procedure/
Method
Written and carefully
followed step-by-step
experiment designed to test
the hypothesis
Next
Data
And
Observations
Information collected during
the experiment
And
Written description of what
was noticed during the
experiment
Finally
Conclusion
Was the hypothesis correct
or incorrect?
Phlogiston Theory
Phlogiston theory of burning
(a) When an object burns
it gives off a substance
called phlogiston.
(b) When the space surrounding
the burning object is filled with
phlogiston, the object will no
longer be able to burn.
Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 4
(a)
(b)
phlogiston
phlogiston
Combustion Theory
Modern theory of burning
(c) When an object burns, it uses
up a substance (oxygen) in
the surrounding space.
(d)
When the space surrounding
the burning object has too little
oxygen in it, the object will no
longer be able to burn.
Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 4
Antoine Lavoiser
(c)
(d)
oxygen
Phlogiston Theory of Burning
1. Flammable materials contain phlogiston.
2. During burning, phlogiston is released
into the air.
3. Burning stops when…
…object is out of phlogiston, or
…the surrounding air contains
too much phlogiston.
Laboratory
Equipment
Zinc Pennies
Copper was used to make
bullet shells in WW II. By
1943, the supply of copper
metal was in short supply. The
US government did not want
to ‘waste’ copper on making
pennies.
Before 1982, all pennies were
solid copper (except 1943).
A shortage of copper drove the
price of copper up in the early
1980s. If melted down, the copper
could be sold for more than one
cent.
Pennies were made with steel
metal. They looked silver.
After 1982, pennies were made
from zinc. A thin coating of
copper was pressed on the zinc.
transmutation
changing one substance into another

Philosopher’s Stone
COPPER

GOLD
In ordinary chemical reactions, we cannot
transmute elements into different elements.
Areas of Chemistry
organic
the study of carboncontaining
compounds
inorganic
everything except
carbon
e.g., compounds
containing metals
physical
measuring physical
properties of
substances
e.g., the melting
point of gold
biochemistry
the chemistry of
living things
Government Regulation of Chemicals
…to protect the…
environment
EPA
consumer
Consumer Product
Safety Commission,
USDA, BATF, FDA
worker
OSHA
Measurements
 science is based
Numbers
 mathematics is
on measurements
based on numbers
 all measurements
have:
- magnitude
- uncertainty
- units
 exact numbers are
obtained by:
- counting
- definition
Graphs
• Line Graph
– Used to show trends or continuous change
• Bar Graph
– Used to display information collected by counting
• Pie Graph
– Used to show how some fixed quantity is broken
down into parts
Convert 41.2 cm2 to m2.
(
)
1m
X m2 = 41.2 cm2 ______
= 0.412 m2
WRONG!
100 cm
= 0.412 cm.m
Recall that…
41.2 cm2 = 41.2 cm.cm
X m2 = 41.2 cm.cm
(
)(
)
1m
______
1m
______
100 cm
100 cm
= 0.00412 m2
X
m2
= 41.2
cm2
(
)
1m
______
100 cm
2
=
0.00412 m2
Convert 41.2 cm2 to mm2.
Recall that…
41.2 cm2 = 41.2 cm.cm
(
X mm2 = 41.2 cm.cm 10
mm
_____
1 cm
)(
1 cm
=
4,120 mm2
10
mm
_____
)
= 4,120 mm2
(
mm
_____
X mm2 = 41.2 cm2 10
1 cm
2
)
Measured dimensions of a rectangular solid:
Length = 15.2 cm
Width = 3.7 cm
Height = 8.6 cm
H
W
Find volume of solid.
L
V=L.W.H
= (15.2 cm)(3.7 cm)(8.6 cm)
3
= 480 cm
Convert to m3.
cm.cm.cm
(
)(
1m
X m3 = 480 cm32 _____
100 cm
1m
_____
)(
100 cm
)
1m
_____
=
100 cm
or
3
(
)
(
3
1m
X m3 = 480 cm3 _____
100 cm
0.000480 m3
=
or
X
m3
= 480
cm3
)
1m
_________
4.80 x 10-4 m3
=
1000000 cm3
Convert to m3...
Measured dimensions of a rectangular solid:
Length = 15.2 cm 0.152 m
Width = 3.7 cm 0.037 m
Height = 8.6 cm 0.086 m H
Find volume of solid.
W
L
V=L.W.H
= (0.152 m)(0.037 m)(0.086 m)
= 0.000480 m3
Convert to mm3.
7.5 x 10-6  - 8.7 x 10-4 = -6.525 x 10-9
report -6.5 x 10-9 (2 sig. figs.)
4.35 x 106  1.23 x 10-3
= 5.3505 x 103 or 5350.5
report 5.35 x 103 (3 sig. figs.)
5.76 x 10-16  9.86 x 10-4
= 5.84178499 x 10-13
report 5.84 x 10-13 (3 sig. figs.)
8.8 x 10  3.3 x 10
11
11
= 2.904 x 1023
report 2.9 x 1023 (2 sig. figs.)
6.022 x 1023  - 5.1 x 10-8 = -3.07122 x 1016
report -3.1 x 1016 (2 sig. figs.)
Rule for Multiplication
Calculating with Numbers Written in Scientific Notation
When multiplying numbers in scientific notation, multiply the
first factors and add the exponents.
Sample Problem: Multiply 3.2 x 10-7 by 2.1 x 105
(3.2) x (2.1) = 6.72
6.72 x 10-2
(-7) + (5) = -2 or 10-2
Exercise: Multiply 14.6 x 107 by 1.5 x 104
2.19 x 1012
Rule for Division
Calculating with Numbers Written in Scientific Notation
When dividing numbers in scientific notation, divide the first
factor in the numerator by the first factor in the denominator.
Then subtract the exponent in the denominator from the
exponent in the numerator.
Sample Problem: Divide 6.4 x 106 by 1.7 x 102
.
(6.4) . (1.7) = 3.76
3.76 x 104
(6) - (2) = 4 or 104
Exercise: Divide 2.4 x 10-7 by 3.1 x 1014
7.74 x 10-22
Rule for Addition and Subtraction
Calculating with Numbers Written in Scientific Notation
In order to add or subtract numbers written in scientific
notation, you must express them with the same power of 10.
Sample Problem: Add 5.8 x 103 and 2.16 x 104
27.4 x 103
2.74 x 104
Exercise: Add 8.32 x 10-7 and 1.2 x 10-5
1.28 x 10-5
(5.8 x 103) + (21.6 x 103) =
Using Scientific Notation
for Expressing the Correct Number of Significant Figures
Measurement
Number of significant
figures it contains
25 g
2
0.030 kg
2
1.240560 x 106 mg
7
6 x 104 sec
1
246.31 g
5
20.06 cm
4
1.050 m
4
Measurement
Number of significant
figures it contains
0.12 kg
2
1240560. cm
7
6000000 kg
1
6.00 x 106 kg
3
409 cm
3
29.200 cm
5
0.02500 g
4
chemical reaction
a rearrangement of atoms such that
“what you end up with”
products
differs from
“what you started with”
reactants
Combustion of a Hydrocarbon
carbon
methane + oxygen 
+ water
dioxide
CH4(g) + 2 O2(g)  CO2(g) + 2 H2O(g)

sodium + water  hydrogen +
sodium
hydroxide
2 Na(s) + 2 H2O(l)  H2(g) + 2 NaOH(aq)

Synthesis
taking small molecules and putting them
together, usually in many steps, to make
something more complex
Sunlight
Carbon
Dioxide
Water
Oxygen
Glucose
Photosynthesis
CO2 + H2O
O2 + C6H12O6
The International System of Units
Quantity
Name
Length
Mass
Time
Amount of substance
Thermodynamic temperature
Electric current
Luminous intensity
meter
kilogram
second
mole
Kelvin
amperes
candela
Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 16
Symbol
m
kg
s
mol
K
amps
cd
Derived Units Commonly
Used in Chemistry
Quantity
Area
Volume
Force
Pressure
Energy
Power
Voltage
Frequency
Electric charge
Name
square meter
cubic meter
newton
pascal
joule
watt
volt
hertz
coulomb
Symbol
m2
m3
N
Pa
J
W
V
Hz
C
Area and Volume: Derived Units
Area = length x width
= 5.0 m x 3.0 m
= 15 ( m x m)
= 15 m2
Volume = length x width x height
= 5.0 m x 3.0 m x 4.0 m
= 60 ( m x m x m)
= 60 m3
Prefixes in the SI System
The Commonly Used Prefixes in the SI System
Prefix
Symbol
Meaning
Power of 10 for
Scientific Notation
_______________________________________________________________________
1,000,000
106
1,000
103
mega-
M
kilo-
k
deci-
d
0.1
10-1
centi-
c
0.01
10-2
milli-
m
0.001
10-3
micro-
m
0.000001
10-6
nano-
n
0.000000001
10-9
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 118
1024 g
1021 g
Quantities of
Mass
1018 g
1015 g
1012 g
Giga-
109 g
Mega-
106 g
Kilo-
103 g
base
100 g
milli-
10-3 g
micro-
10-6 g
nano-
10-9 g
pico-
10-12 g
femto-
10-15 g
atomo-
10-18 g
Ocean liner
Indian elephant
Average human
1.0 liter of water
Grain of table salt
10-21 g
10-24 g
Kelter, Carr, Scott, Chemistry A Wolrd of Choices 1999, page 25
Earth’s atmosphere
to 2500 km
Typical protein
Uranium atom
Water molecule
SI-US Conversion Factors
Relationship
Conversion Factors
Length
2.54 cm = 1 in.
2.54 cm
1 in
and
1 m = 39.4 in.
39.4 in
1m
and
946 mL = 1 qt
946 mL
1 qt
and
1 qt
946 mL
1 L = 1.06 qt
1.06 qt
1L
and
1L
1.06 qt
and
1 lb
454 g
and
1 kg
2.20 lb
1 in
2.54 cm
1m
39.4 in.
Volume
Mass
454 g = 1 lb
1 kg = 2.20 lb
454 g
1 lb
2.20 lb
1 kg
Accuracy vs. Precision
Good accuracy
Good precision
Poor accuracy
Good precision
Poor accuracy
Poor precision
Systematic errors:
reduce accuracy
(instrument)
Random errors:
reduce precision
(person)
Precision
Accuracy
 reproducibility
 correctness
 check by
repeating
measurements
 check by using a
different method
 poor precision
results from poor
technique
 poor accuracy
results from
procedural or
equipment flaws.
Errors
Systematic
Errors in a single direction (high or low)
Can be corrected by proper calibration or
running controls and blanks.
Random
Errors in any direction.
Can’t be corrected. Can only be accounted
for by using statistics.
Accuracy Precision Resolution
time offset [arbitrary units]
3
not accurate, not precise
accurate, not precise
not accurate, precise
accurate and precise
accurate, low resolution
2
1
0
-1
-2
-3
subsequent samples
SI Prefixes
kilodecicentimilli-
1000
1/
10
1/
100
1/
1000
Also know…
1 mL = 1 cm3 and 1 L = 1 dm3
SI System for Measuring Length
The SI Units for Measuring Length
Unit
Symbol
Meter Equivalent
_______________________________________________________________________
1,000 m or 103 m
kilometer
km
meter
m
1
decimeter
dm
0.1 m or 10-1 m
centimeter
cm
0.01 m or 10-2 m
millimeter
mm
0.001 m or 10-3 m
micrometer
mm
0.000001 m or 10-6 m
nanometer
nm
0.000000001 m or 10-9 m
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 118
m or 100 m
Practice Measuring
Timberlake, Chemistry 7th Edition, page 7
0
cm
1
2
3
4
5
4.5 cm
0
cm
1
2
3
4
5
4.54 cm
0
cm
1
2
3
4
5
3.0 cm
Implied Range of Uncertainty
3
4
5
6
Implied range of uncertainty in a measurement reported as 5 cm.
3
4
5
6
Implied range of uncertainty in a measurement reported as 5.0 cm.
3
4
5
6
Implied range of uncertainty in a measurement reported as 5.00 cm.
Dorin, Demmin, Gabel, Chemistry The Study of Matter 3rd Edition, page 32
10
760
5
0
Here is a final example, with the vernier at yet
another position. The pointer points to a value that is
obviously greater than 751.5 and also less than
752.0. Looking for divisions on the vernier that match
a division on the scale, the 8 line matches fairly
closely. So the reading is about 751.8.
750
740
In fact, the 8 line on the vernier appears to be a little
bit above the corresponding line on the scale. The 8
line on the vernier is clearly somewhat below the
corresponding line of the scale. So with sharp eyes
one might report this reading as 751.82 ± 0.02.
This "reading error" of ± 0.02 is probably the correct
error of precision to specify for all measurements
done with this apparatus.
http://www.upscale.utoronto.ca/PVB/Harrison/Vernier/Vernier.html
How to Read a Thermometer
(Celcius)
4.0 oC
10
10
100
5
5
50
0
0
0
8.3 oC
64 oC
5
0
3.5 oC
Record the Temperature
A
(Celcius)
60oC
6oC
50oC
5oC
25oC
100oC
100oC
40oC
4oC
20oC
80oC
80oC
30oC
3oC
15oC
60oC
60oC
20oC
2oC
10oC
40oC
40oC
10oC
1oC
5oC
20oC
20oC
0oC
0oC
0oC
0oC
0oC
30.0oC
B
3.00oC
C
19.0oC
D
48oC
E
60.oC
Rules for Counting Significant Figures
1. Nonzero integers always count as significant figures.
2. Zeros: There are three classes of zeroes.
a.
Leading zeroes precede all the nonzero digits and DO NOT count as
2 significant figures.
significant figures. Example: 0.0025 has ____
b.
Captive zeroes are zeroes between nonzero numbers. These always
4 significant figures.
count as significant figures. Example: 1.008 has ____
c.
Trailing zeroes are zeroes at the right end of the number.
Trailing zeroes are only significant if the number contains a decimal point.
3 significant figures.
Example: 1.00 x 102 has ____
Trailing zeroes are not significant if the number does not contain a decimal
1 significant figure.
point. Example: 100 has ____
3.
Exact numbers, which can arise from counting or definitions such as 1 in
= 2.54 cm, never limit the number of significant figures in a calculation.
Ohn-Sabatello, Morlan, Knoespel, Fast Track to a 5 Preparing for the AP Chemistry Examination 2006, page 53
Significant figures: Rules for zeros
Leading zeros are not significant.
Leading zero
0.421 – three significant figures
Captive zeros are significant.
Captive zero
4012 – four significant figures
Trailing zeros are significant.
Trailing zero
114.20 – five significant figures
Significant Figures
Number of
Significant
Figures
Quantity
Certain
Digits
Uncertain
Digits
14.379 g
1437
9 (thousandths)
5
60
2 (hundredths)
3
12058
0 (thousandths)
6
7.5 g
7
5 (tenths)
2
0.037 g
3
7 (thousandths)
2
0.0370 g
37
0 (ten-thousandths) 3
6.02 mL
120.580 m
*The position of the decimal point has nothing to do with the number of significant figures.
Ralph A. Burns, Fundamentals of Chemistry 1999, page 52
Basic Algebra
Solve for x.
One way to solve this
is to cross-multiply.
Then, divide both
sides by TR.
The answer is…
___
BA = ___
TR
x
H
BAH = xTR
( )
( )
___
1 BAH = xTR ___
1
TR
TR
BAH
x = ___
TR
Solve for T2, where…
P
1V1
____
=
P1 = 1.08 atm
T1
P2 = 0.86 atm
____
1 PVT =
V1 = 3.22 L
1 1 2
P
V
1
1
V2 = 1.43 L
P2V2T1
T1 = 373 K
( )
P
2V 2
____
T2
( )
____
1
P1V1
P2V2T1
______
T2 =
P1V1
(0.85
atm)(1.43 L)(373 K)
_____________________
T2 =
= 130 K
(1.08 atm)(3.22 L)
A General Procedure for
Solving Problems
• Read the problem carefully and make a list of
the “knowns” and the ‘unknowns”
• Look up all needed information
– Your lecture notes will have much, if not all, of the
needed information
• Work out a plan and, following your plan, obtain
an answer by carrying out the required math.
• Check over your work
– This is best done by estimating your answer
– Ask yourself: “Does the answer seem reasonable?”
How to Succeed in Chemistry
•
•
•
•
•
Learn the language
Use the illustrations
Review your notes frequently
Work as many problems as possible
Do NOT cram for exams.