Transcript Unit 1 Introduction to Chemistry

Outlin
e
Unit 1
Introduction to Chemistry
PowerPoint Presentation adapted from Mr. John Bergmann
Whether you
you
can do and
a thing
Problems
call believe
forth our
courage
our wisdom;
or believe
you
can’t,
indeed,
they
create
our courage and our wisdom.
you
arebecause
right. of problems that we grow mentally
itDon’t
is only
be afraid to take a big step
and
spiritually.
It is through the pain of
if
one
is
indicated.
Henry Ford, 1863-1947 American Car Manufacturer
confronting
resolving problems
You
can’t crossand
a chasm
that
we learn.
in two small
jumps.
David Lloyd George, 1863-1945
British
Prime
Minister
and Statesman
M. Scott
Peck,
b. 1936
American
Psychiatrist and Writer
All through my life,
the new sights of Nature
Believe that life is worth living,
made me rejoice like a child.
and your belief will help create the fact.
Marie
Curie, 1867-1934
Polish-Born
French Chemist
William James, 1842-1910
American
Psychologist
and Philospher
Chemistry is the study of matter
and the transformations it can
undergo…
…Matter is anything that has
mass and occupies space.
Chemistry
with a
Purpose
Interactive Periodic Table
S P Ar Ta N S
16
1
15
18
73
7
16
The Human Element
H
H
He
1
2
1
2
3
Li
Be
B
C
N
O
F
Ne
3
4
5
6
7
8
9
10
Al
Si
P
S
Cl
Ar
13
14
15
16
17
18
Na Mg
11
4
K
19
5
7
Ca Sc
Ti
V
Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br
Kr
23
24
35
36
I
Xe
53
54
20
21
22
Rb Sr
Y
Zr Nb Mo Tc Ru Rh Pd Ag Cd
In
39
40
41
42
49
Hf
Ta
W
72
73
74
37
6
12
38
Cs Ba
55
56
Fr
Ra
87
88
*
W
25
43
26
44
Re Os
75
76
27
28
29
47
30
45
46
Ir
Pt Au Hg
Tl
77
78
81
79
48
31
80
32
33
34
Sn Sb Te
50
51
Pb Bi
82
83
52
Po At Rn
84
85
86
Rf Db Sg Bh Hs Mt
104
105
106
107
108
109
La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
57
58
59
Ac Th Pa
89
90
91
60
U
92
61
62
63
64
65
66
Np Pu Am Cm Bk Cf
93
94
95
96
97
98
67
68
69
70
71
Es Fm Md No Lr
99
100
101
102
103
Natural Science
Physical Science
Physics
Chemistry
Earth and Space Science
Geology
Astronomy
Meteorology
Life Science
Botany
Ecology
Oceanography
Natural science covers a very broad range of knowledge.
Wysession, Frank, Yancopoulos, Physical Science Concepts in Action, 2004, page 4
Zoology
Genetics
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
Job Skills for the Future
•
•
•
•
•
•
•
•
•
Evaluate and Analyze
Think Critically
Solve Math Problems
Organize and Use References
Synthesize Ideas
Apply Ideas to New Areas
Be Creative
Make Decisions with Incomplete Information
Communicate in Many Modes
Chemistry will develop ALL of these skills in YOU!
Dual
Perceptions
Dual
Perceptions
Stack of Blocks
Perception of Motion
Click to see
VIDEO
A Colorful Demonstration: The Remsen Reaction
Safety
Basic Safety Rules
#1 Rule: Use common sense.
Others:
No horseplay.
No unauthorized experiments.
Handle chemicals/glassware with respect.
Safety Features of the Lab
safety shower
fire blanket
fire extinguisher
eye wash
fume hood
circuit breaker switch
Material Safety Data Sheet
(MSDS)
-- gives information
about a chemical
-- lists “Dos” and “Don’ts;”
emergency procedures
Chemical Exposure
acute exposure
a one-time
exposure
causes damage
e.g., reaction to drugs
or medication
chronic exposure
damage occurs
after repeated
exposure
e.g., smoking,
asbestos
Government Regulation of
Chemicals
The government regulates chemicals to reduce
the risk to the…
• Consumer
FDA, USDA, Consumer Product Safety Commission
• Worker
OSHA
• Environment
EPA
Chemical Stewardship
Flammable
Chemical Burns
Health
Reactive
Special
Chemical burns on feet.
Skin burned by chemicals
SAFETY in the Science
Classroom
Obey the safety contract
–
–
–
–
–
–
Use common sense
No unauthorized experiments
Wear safety glasses
Safety is an attitude!
Don’t take anything out of lab
Read and follow all instructions
LD50
the lethal dosage for 50%
of the animals on which
the chemical is tested
There are various ways an LD50 can be
expressed. For example, acetone has
the following LD50s:
ORL-RAT LD50: 5,800 mg/kg
IHL-RAT LD50: 50,100 mg/m3-h
SKN-RBT LD50: 20 g/kg
Example
Chemical A: LD50 = 3.2 mg/kg
Chemical B: LD50 = 48 mg/kg
Which is more toxic?
Chemical A is more toxic because less of it
proves fatal to half of a given population.
Science
The Functions of Science
pure science
applied science
the search for
knowledge; facts
using knowledge
in a practical way
e.g., aluminum
strong
lightweight
good conductor
Science attempts to establish
cause-effect relationships.

risk-benefit analysis
weigh pros and cons before deciding
Because there are many considerations for
each case, “50/50 thinking” rarely applies.
How does scientific
knowledge advance?
1. curiosity
2. good observations
3. determination
4. persistence
The Scientific Method
** Key: Be a good observer.
observation
uses the five
senses
inference
involves a judgment
or assumption
Types of Data
Observations are also called data.
qualitative data
-- descriptions
e.g., clear liquid
quantitative data
-- measurements
e.g., 55 L or 83oC
Parts of the Scientific Method
Identify an unknown.
Make a hypothesis: a testable prediction
Repeatedly experiment to test
hypothesis.
procedure: order of events in
experiment (i.e., a recipe)
variable: any factor that could
influence the result
A Scientific
Experiment
Experiments must be controlled:
they must have two set-ups
that differ by only one variable
conclusion: must be based on the data
Scientific Law vs. Scientific Theory
law: states what happens
-- does not change
-- never violated
-- e.g., law of gravity,
laws of conservation
theory: tries to explain why or
how something happens
-- based on current evidence
-- e.g., Theory of Gravity,
Atomic Theory
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.
(superceded by combustion theory of burning)
Chemistry
The Beginning
early practical chemistry:
household goods, weapons,
soap, wine, basic medicine
The Greeks believed there
were four elements.
___
___
D
D
earth
wind
fire
~
water
D
Alchemy
(~500 – 1300 C.E.)
the quest for the Philosopher’s Stone
(the elixir, the Sorcerer’s Stone)
Allegedly, this substance would turn
cheap metals into gold.
Alchemical symbols for substances…
GOLD
SILVER
COPPER
IRON
.
..
...
....
.....
SAND
transmutation: changing one substance
into another
Philosopher’s
Stone

COPPER
GOLD
In ordinary chemical reactions…we cannot
transmute elements into different elements.
Alchemy was practiced in many regions of the
world, including China and the Middle East.
Alchemy arrived in western Europe
around the year 500 C.E.
Modern chemistry evolved from alchemy.
Contributions
of alchemists:
• experimental techniques
• new glassware
• information about elements
• developed several alloys
What is Chemistry?
the study of matter
and its changes
Areas of Chemistry
organic
the study of carboncontaining
compounds
inorganic
studies everything
except carbon
e.g., compounds
containing metals
biochemistry
the chemistry of
living things
physical
measuring physical
properties of
substances
e.g., the melting
point of gold
Careers in Chemistry
•
•
•
•
•
•
research (new products)
production (quality control)
development (manufacturing)
chemical sales
software engineering
teaching
The skills you will develop by an earnest
study of chemistry will help you in any
career field.
The Scope of Chemistry
bulk chemical manufacturing
acids, bases, fertilizers
**sulfuric acid (H2SO4) = #1 chemical
petroleum products
fuels, oils, greases, asphalt
pharmaceuticals
1 in 10,000 new products
gets FDA approval
synthetic fibers
nylon, polyester, rayon , spandex
All fields of endeavor
are affected by chemistry.
Government Regulation of Chemicals
worker
OSHA
environment
EPA
The government
regulates chemicals
to protect the…
FDA
USDA
FAA
CPSC consumer
Manipulating Numerical Data
Graphs
Bar Graph
shows how many of something
are in each category
Chemistry Grades
# of students
10
8
6
4
2
0
A
B
C
D
F
Pie Graph
shows how a whole is broken into parts
Percentage of
Weekly Income
Entertainment (40%)
Food (25%)
Clothing (20%)
Savings (15%)
Line Graph
shows continuous change
Stock Price over Time
Share Price ($)
60
50
40
30
20
10
0
Jan
Feb
Mar
Apr
Month
In chemistry…you will always use a line graph.
Elements of a “good” line graph
Temp. v. Vol. for a Gas at Constant
Pressure
2. axes labeled,
with units
3. neat
4. use the
available space
Volume (L)
1. title
10
9
8
7
6
5
4
3
2
1
0
120
140
160
180
200
Temp. (K)
220
240
Essential Math of Chemistry
Scientific Notation
-- used to express very large or very small
numbers, and/or to indicate precision
(i.e., to maintain the correct number
of significant figures)
Form:
(# from 1 to 9.999) x 10exponent
800 = 8 x 10 x 10
= 8 x 102
2531 = 2.531 x 10 x 10 x 10
= 2.531 x 103
0.0014 = 1.4 10 10 10
= 1.4 x 10–3
  
Put in standard form.
1.87 x 10–5 = 0.0000187
3.7 x 108 = 370,000,000
7.88 x 101 = 78.8
2.164 x 10–2 = 0.02164
Change to scientific notation.
12,340 = 1.234 x 104
0.369 = 3.69 x 10–1
0.008 = 8 x 10–3
1,000,000,000 = 1 x 109
6.02 x 1023 = 602,000,000,000,000,000,000,000
Using the Exponent Key
EE
EXP
The EE or EXP or E key means “times 10 to the…”
How
How to
to type
type out
out 6.02
6.02 xx10
102323::
6
0
.
2
EE
2
3
not…
WRONG!
6
0
.
yx
2
2
3
or…
6
WRONG!
.
0
2
x
1
and not…
6
.
0
EE
2
3
TOO MUCH WORK.
0
2
x
1
0
yx
2
3
Also, know when to hit your (–) sign.
(before the number,
after the number,
or either one)
1.2 x 105

2.8 x 1019
Type this calculation in like this:
1
.
2
EE
5
2
.
8
EE
1

9
=
Calculator gives… 4.2857143 –15
or… 4.2857143 E–15
This is NOT written… 4.3–15
But instead is written… 4.3 x 10–9
or
4.3 E –9
7.5 x 10–6 (–8.7 x 10–14) = –6.5 x 10–19
4.35 x 106 (1.23 x 10–3) = 5.35 x 103 or 5350
5.76 x 10–16

9.86 x 10–4 = 5.84 x 10–13
8.8 x 1011 x 3.3 x 1011 = 2.9 x 1023
Essential Math
of Chemistry
Units must be carried into the
answer, unless they cancel.
5.2 kg (2.9 m) = 0.64 kg-m
(18 s)(1.3 s)
s2
4.8 kg (23 s)
(18 s)(37 s)
= 0.57 kg
s
Solve for x.
x+y=z
x and y are connected by
addition. Separate them
using subtraction. In general,
use opposing functions to
separate things.
x+y=z
–y –y
The +y and –y cancel on
the left,
leaving us with…
x=z–y
Numerical Example
Solve for x.
x – 24 = 13
x and 24 are connected by
subtraction. Separate
them using the opposite
function: addition.
x – 24 = 13
+24 +24
The –24 and +24 cancel
on the left,
leaving us with…
x = 37
Solve for x.
x and k are connected by
multiplication. Separate
them using the opposite
function: division.
The two k’s cancel on
the right,
leaving us with…
F=kx
()
()
__
1
__
1
F=kx
k
k
(or)
F=kx
k k
__
F
x=
k
Numerical Example
Solve for x.
x and 7 are connected by
multiplication. Separate
them using the opposite
function: division.
The two 7’s cancel on
the right,
leaving us with…
8=7x
()
()
__
1
__
1
8=7x
7
7
(or)
8=7x
7 7
__
8
x=
7
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
P1V1 1 1 2
V2 = 1.43 L
P2V2T1
T1 = 373 K
( )
P
2V 2
____
T2
( )
____
1
P1V1
P2V2T1
______
T2 =
P1V1
(0.86
atm)(1.43 L)(373 K)
_____________________
T2 =
= 132 K
(1.08 atm)(3.22 L)
SI Prefixes
kilodecicentimilli-
(k)
(d)
(c)
(m)
1000
1/
10
1/
100
1/
1000
Also,
1 mL = 1 cm3 and 1 L = 1 dm3
Conversion Factors
and
Unit Cancellation
How many cm are in 1.32 meters?
equality: 1 m = 100 cm
(or 0.01 m = 1 cm)
conversion factors:
______
1m
100 cm
or
(
100 cm
______
1m
)
100 cm = 132 cm
1.32 m ______
1m
We use the idea of unit cancellation
to decide upon which one of the two
conversion factors we choose.
How many m is 8.72 cm?
equality: 1 m = 100 cm
conversion factors:
______
1m
100 cm
or
(
100 cm
______
1m
)
1m
8.72 cm ______
= 0.0872 m
100 cm
Again, the units must cancel.
How many kilometers is
15,000 decimeters?
( )(
1m
15,000 dm ____
10 dm
)
1 km
______
= 1.5 km
1,000 m
How many seconds
is 4.38 days?
( )(
24 h
4.38 d ____
1d
)( )
60
min
_____
1h
60 s
____
= 378,432 s
1 min
If we are accounting for significant
figures, we would change this to…
3.78 x 105 s
Simple Math
with
Conversion Factors
Find area of rectangle.
4.6 cm
A=L.W
= (4.6 cm)(9.1 cm)
= 42
9.1 cm
2.
cm cm
Convert to m2.
cm.cm
1m
42 cm2 ______
100 cm
(
)
= 0.0042 m2
(
)
= 4200 mm2
10 mm
Convert to mm2. 42 cm2 ______
1 cm
2
2
For the rectangular solid:
Length = 14.2 cm
Width = 8.6 cm
Height = 21.5 cm
Find volume.
V=L.W.H
= (14.2 cm)(8.6 cm)(21.5 cm)
= 2600 cm3
Convert to mm3.
2600
cm3
(
)
10 mm
______
1 cm
3
= 2,600,000 mm3
= 2.6 x 106 mm3
mm and cm differ by a factor of………. 10
mm2 “ cm2 “
“ “
“
“ ………. 100
mm3 “ cm3 “
“ “
“
“ ………. 1000
Basic Concepts in Chemistry
chemical: any substance that takes part in,
or occurs as a result of,
a chemical reaction
All matter can be considered to be
chemicals or mixtures of chemicals.
chemical reaction: a rearrangement of
atoms such that…
“what you end up with”
products
differs from
“what you started with”
reactants
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)

Law of Conservation of Mass
total mass
total mass
=
of products
of reactants
Pmass = Rmass
synthesis: taking small
molecules and putting
them together, usually
in many steps, to make
something more complex
JENNY
How many feet is 39.37 inches?
equality: 1 ft = 12 in
applicable conversion factors:
______
1 ft
12 in
X ft = 39.37 in
or
______
12 in
1 ft
( )
____
1 ft
= 3.28 ft
12 in
Again, the units must cancel.
Resources - Intro. to Chemistry
Worksheet - vocabulary
Worksheet - material safety data sheet (acetone)
Activity - checkbook activity
Worksheet - graphing
Worksheet - real life chemistry
Worksheet - conversion factors
Worksheet - scientific notation
Worksheet - metric article (questions)
Episode 1 - The World of Chemistry
Worksheet - significant digits
Episode 3 – Measurement:
The Foundation of Chemistry
Worksheet - math review
Episode 4 - Modeling The Unseen
Worksheet - math of chemistry
Worksheet - article on the metric system
Textbook - questions
Lab – introduction to qualitative analysis
Outline (general)