1. Unit 1 Introduction to Chemistry
Internet web site:

2. Material Safety Data Sheet (MSDS)--
gives information
about a chemical
-- lists “Dos” and “Don’ts;”
emergency procedures

3. a one-time exposure that causes damage
Chemical Exposure
acute exposure vs. chronic exposure
a one-time exposure that causes damage
damage occurs after repeated exposure
e.g.
reaction to drugs
or medication
e.g.
smoking,
asbestos

4. How Toxic is “Toxic?” Chemicals may cause harm in many different ways:
Flammable
Explosive
Radioactive
Corrosive
Irritant
Carcinogenic
Mutagenic
Teratogenic

5. 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/m3h
SKN-RBT LD50: 20 g/kg

6. LD50 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 is necessary to kill half of a given population

7. Science

8. The Functions of Science
pure science applied science
the search for
knowledge; facts
using knowledge
in a practical way
e.g., properties of aluminum
strong
lightweight
good conductor

9. Corning Glass NASA’s Problem Design a material Corning Glass Company
that is clear and can with-
stand extreme differences
in temperature without fail-
ing (cracking).
Design a face shield
to protect and provide
clear vision.
Corning Glass Company
FAILED…but
SUCCEEDED at making
great cookware that can
withstand extremes in temperature.
Often times in science, great discoveries are made serendipitously or by accident. People set out with a goal in mind and discover something else, quite remarkably.

10. Aluminum Mining 1850s: aluminum sold for $500 / lb Charles Martin Hall
4-6 pounds bauxite
current
1 lb Al + =
1850s: aluminum sold for $500 / lb
Charles Martin Hall
Developed method to extract aluminum from bauxite
Hall’s method
As a result, $0.30/lb
Charles Martin Hall ( ) was motivated by a professor at Oberlin College who remarked that anyone discovering a cheap method of producing aluminum would become rich and famous. Hall's discovery, in his home laboratory within eight months of his graduation, was the foundation of the aluminum industry in the United States.
Paul Heroult ( ) a student of LeChatelier's, was, like Hall, 23 years old when he discovered the same method of producing aluminum. Heroult's discovery was the foundation of the aluminum industry in Europe.
Earth's crust is ~8.3% by mass of aluminum. This makes aluminum the third most abundant element and the most abundant metal. Aluminum metal was not isolated until 1825, when Hans Oersted produced it in a pure form. It was considered a semi-precious metal (rare and expensive) in 1884 when an aluminum cap was placed on the Washington monument.

11. Science attempts to establish cause/effect relationships
Science can NEVER prove a cause/effect relationship, only make a correlation…

12. risk-benefit analysis weigh pros and cons before deciding
Because there are many considerations for each case, “black/white thinking” rarely applies. It is usually shades of grey.

13. How does scientific knowledge advance?
1. curiosity
2. determination
3. persistence
4. good observations

14. The Scientific Method

15. ** Key: Be a good observer.
observation inference
uses the five
senses
involves a judgment
or an assumption

16. Observations are also called data.
Types of Data
Observations are also called data.
qualitative data quantitative data --
descriptions --
measurements
e.g.,
colorless liquid
e.g.,
17 mL; 83oC
(vs. clear liquid)

17. Candle Observation Activity
This cartoon is used the day after we perform the "Observations of a Burning Candle Lab" for a humorous set induction.

18. A Description of a Burning Candle
A photograph of a burning candle is shown1 in the upper right corner. The candle is cylindrical2 and has a diameter3 of about 3 cm. The length of the candle was initially about 16 centimeters4, and it changed slowly5 during observation, decreasing about 1 cm in one hour6. The candle is made of a translucent7, white8 solid9 which has a slight odor10 and no taste11. It is soft enough to be scratched
with the fingernail12. There is a wick13 which extends from top to bottom14 of the candle along its
central axis15 and protrudes about 5 mm above the top of the candle16. The wick is made of
three strands of string braided together17.
A candle is lit by holding a source of flame close to the wick for a few seconds. Thereafter the
source of flame can be removed and the flame sustains itself at the wick18. The burning candle
makes no sound19. While burning, the body of the candle remains cool to the touch20 except near
the top. Within about 1.5 cm of the top the candle is warm21 (but not hot) and sufficiently soft
to mold easily22.
The flame flickers in response to air currents23 and tends to become quite smoky while flickering24.
In the absence of air currents, the flame is of the form shown in the photograph, though it retains some movement at all times25. The flame begins about 2 mm above the top of the candle26, and at its
base the flame has a blue tint27. Immediately around the wick in a region about 2 mm wide and extending about 5 mm above the top of the wick28 the flame is dark29. This dark region is roughly conical in shape30. Around this zone and extending about 1 cm above the dark zone is a
region which emits yellow light31, bright but not blinding32. The flame has rather sharply defined
sides33 but a ragged top34. The wick is white where it emerges from the candle35, but from the base
of the flame to the end of the wick36 it is black, appearing burnt, except for the last 0,5 cm, where it glows red37. The wick curls over about 3 mm from its end38. As the candle becomes shorter, the wick shortens too, so as to extend roughly a constant length above the top of the candle39. Heat is emitted
by the flame40, enough so that it becomes uncomfortable in 10 to 20 seconds if one holds his finger
10 cm to the side of the quiet flame41 or 10 – 12 cm above the flame42.
Burning a Candle
“Wax is a mixture of compounds containing chiefly carbon and hydrogen. When the wick is lit, some wax is drawn up the wick and vaporizes. The vapor burns, using oxygen in the air. The yellow part of the flame is caused by carbon particles incandescing (glowing) at high temperatures. Unburned carbon forms soot.”
Eyewitness Science “Chemistry” , Dr. Ann Newmark, DK Publishing, Inc., 1993, pg 30

19. 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 of what was done)
variable:
any factor that could
influence the result

20. A Scientific Experiment
Experiments must be controlled:
Only one variable can change at a time
Independent variable:
a variable you control and manipulate (x-axis)
Dependent variable:
the variable you measure as you change I.V. (y-axis)
conclusion: must be supported with evidence from the data collected

21. A Controlled Experiment?

22. Scientific Method Make observation Ask question Develop hypothesis
Test hypothesis
with an
experiment
Test hypothesis
with further
experiments
Revise
hypothesis
Analyze data
and draw
conclusions
Hypothesis IS
supported
Hypothesis
is NOT
supported
Develop
theory
Wysession, Frank, Yancopoulos,
Physical Science Concepts in Action, 2004, page 8

23. Scientific Law vs. Scientific Theory
states what happens, i.e., a relationship between various quantities --
Laws are often written in
the form of… an equation.
-- e.g.,
Newton’s law of gravity,
laws of conservation

24. a scanning tunneling microscope (STM)
theory:
tries to explain WHY or
HOW something happens --
based on current evidence
-- e.g.,
Theory of Gravity,
Atomic Theory
images of nickel atoms
taken by an STM
a scanning tunneling microscope (STM)

25. 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)

26. ________________________________Dollars
Rob L. Brown, Sr. or Mary H. Brown
1007 Shady Lane
Normal, Illinois
Date_________
Pay to the
Order of $
________________________________Dollars
NATIONAL CITY BANK OF MICHIGAN/ILLINOIS
SPRINGFIELD, ILLINOIS
Memo________________ ___________________________
: :
Blank Checks
Rob L. Brown, Sr.
1437 Tampa Avenue, Apt. J-432
Bloomington, Illinois
Date_________
Pay to the
Order of $
________________________________Dollars
Illinois State Bank
CHICAGO , ILLINOIS
Memo________________ ___________________________
: :

27. Chemistry

28. The Greeks believed there were four elements
The Beginning
Early practical chemistry:
household goods, weapons,
soap, wine, basic medicine
The Greeks believed there
were four elements ~ D
___ D D
___
earth wind fire water

29. Allegedly, this substance would turn cheap metals into gold
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

30. changing one substance into another
transmutation:
changing one substance
into another
COPPER
GOLD 
Philosopher’s
Stone
In ordinary chemical reactions…
we cannot
transmute elements into different elements

31. 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.

32. Contributions of alchemists:
experimental techniques
new glassware
information about elements
developed several alloys

33. What is chemistry?
the study of matter
and its changes

34. Areas of Chemistry organic biochemistry the study of carbon
containing compounds
the chemistry of
living things
inorganic
physical
studies everything
except carbon
e.g., compounds
containing metals
measuring physical
properties of
substances
e.g., the melting
point of gold

35. Careers in Chemistry research (new products)
production (quality control)
development (manufacturing)
chemical sales
software engineering
teaching

36. The skills you will develop by an earnest study
of chemistry will help you in any career field.

37. 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 drugs
gets FDA approval
synthetic fibers
nylon, polyester, rayon ,
spandex

39. Colloidal Silver
Used to treat fungal infections, skin rashes, Lyme disease, HIV/Aids and food poisoning

40. OK Supplements
Calcium, Cranberry, Fish Oil, Vitamin D, Lactobacilius

41. Chemistry impacts:
everyone
all fields of endeavor

42. Government Regulation of Chemicals
The various levels of government regulate
chemicals to protect the:
environment
worker
EPA
OSHA
consumer
OSHA: Occupational Safety and Health Admin.
CPSC: Consumer product safety commission
FDA
USDA
CPSC

43. Manipulating Numerical Data

44. Graphs

45. shows how many of something are in each category
Bar Graph
shows how many of something are in each category
# of students

46. shows how a whole is broken into parts
Pie Graph
shows how a whole is broken into parts
Percentage of
Weekly Income

47. shows continuous change
Line Graph
shows continuous change
Stock Price over Time
In chemistry…
you will always use a line graph.

48. Elements of a “good” line graph
1. title
2. axes labeled, with units
3. neat
4. use the available space

49. Graphing HW
Time
Total Dist. cycled (km)
8 a.m.
9 a.m. 12
10 a.m. 23
11 a.m. 33
noon 42
1 p.m. 50
2 p.m. 57
3 p.m. 63
4 p.m. 68
Distance Cycled (km)
Time (h)
Extrapolation: predicting a pattern outside of a data set using the graph
Interpolation: estimating a data point within the set of data using the pattern of the graph

50. Essential Math of Chemistry

51. Scientific Notation
…used to express very large or very small numbers. Also used to maintain correct SF.
Form: (# from 1 to 9.999) x 10exponent
800 = 8 x 10 x 10
= 8 x 102
2531 = x 10 x 10 x 10
= x 103 =
= 1.4 x 10–3
(-) exponent = number < 1
(+) exponent = number > 1

52. Put in standard form
1.87 x 10–5 =
3.7 x 108 = 370,000,000
7.88 x 101 = 78.8
2.164 x 10–2 =
Change to scientific notation
12,340 = 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

53. Using the Exponent Key EE
EXP

54. The EE or EXP or E key means “times 10 to the…”
How to type out 6.02 x 1023:
How to type out 6.02 x 1023: 6 EE . 3 2 6 EE . 3 2
not…
WRONG! 6
y x . 3 2
WRONG!
or… x 1 6 . 2 EE 3
and not…
TOO MUCH WORK.
y x 3 2 x 1 6 .

55. Also, know when to hit your (–) sign.
(before the number,
after the number,
or either one)

56. 1.2 x 105
2.8 x 1019 = 1 . 2 EE 5 9 8
Type this calculation in like this:
–15
Calculator gives…
E–15
or…
This is NOT written…
4.3–15
But instead is written…
4.3 x 10–15 or
4.3 E –15

57. 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– x 10–4 =
5.84 x 10–13
8.8 x 1011 x 3.3 x 1011 =
2.9 x 1023

58. Accuracy and Precision
All numerical data are the result
of uncertain measurements.
precision: a measure of the degree of
fineness of a measurement; it
depends on the extent to which the
instrument is calibrated
e.g.,
8 m
vs m
vs m

59. When repeated, precise measurements yield similar answers each time.
e.g., precise…
0.653 m
0.652 m
0.654 m
imprecise…
0.7 m
0.8 m
0.6 m
A good rule of thumb is…
It is the % difference that is important.

60. Three types of error can affect accuracy.
how close a measured
value is to the true value
Three types of error can affect accuracy.
human error:
mistake in reading instrument
or recording results
-- minimize with repeated measurements
method error:
using measuring instrument improperly
e.g., parallax in measuring with a meter stick
instrument error:
measuring device is
improperly calibrated
e.g., bathroom scale that always reads 5 lbs. too heavy

61. Significant Figures
about…
A student is combining separate water samples, all of differing volumes, into one large bucket. Samples A, B and C are 25.5 mL, mL and 51 mL, respectively. Once combined, what is the total volume of all the samples?
92.87 mL
NO!
Because the samples were each measured with a different level of precision, we must factor that into our calculations by identifying what are called significant figures.

62. Measurement and Precision
The last digit of any measured number is assumed to be an estimate (uncertain)
The second to last digit is assumed to be known with certainty
A (25.5 mL) B (16.37 mL) C (51 mL)
(think dashes…) 26 60 50 25
16.4
16.3

63. Identifying Significant Figures
Counting SF in a number
Non-zero numbers: ALWAYS count as SF
Zeroes
Left: NEVER count as SF ( )
Middle: ALWAYS count as SF (5001)
Right: sometimes…
w/ decimal point: count as SF (25.10)
w/o decimal point: DO NOT count as SF (8200)
Exact Numbers: IGNORE SF
(assumed to have an infinite number of SF)
Counts (28 students in this class)
Constants (1 mol = x 1023)
Conversions (1 in = 2.54 cm)
Relative to the non-zero numbers

64. How many Sig Figs? Measurement Number of SF Measurement Number of SF 2
0.030 kg
x 106 mg
6 x 104 sec g
20.06 cm
1.050 m 2 7 1 5 4
0.12 kg cm kg
6.00 x 106 kg
409 cm dm g 2 7 1 3 5 4
Now, determine the # of SF in Part A and B of the Sci. Not. HW (5 min)

65. Sig Figs with Calculations
Note: For any calculations, always perform the entire calculation without rounding, and then round the final answer.
Addition/Subtraction
Round the answer to the LEAST number of decimal places found (least precise) =
Multiplication/Division
Round the answer to the smallest number of SF found
5.282 x 3.42 =
→ rounded to 48.7
→ rounded to 18.1
(3.42 only has 3 SF)

66. Back to the original question…
A student is combining separate water samples, all of differing volumes, into one large bucket. Samples A, B and C are 25.5 mL, mL and 51 mL, respectively. Once combined, what is the total volume of all the samples?
25.5 mL mL + 51 mL = mL
93 mL
Could I write that as 93.0?
NO!

67. Round to the correct number of significant figures. Calculator says…
2 sig. figs.
3 sig. figs.
5 sig. figs.
75.6
387600
4200
8.4845E-4 76
75.6
75.600
0.53
0.528
390,000
388,000
* x 105
4,200
* 4.20 x 103
x 103
8.5 x 10–4
8.48 x 10–4
x 10–4
* = requires scientific notation

68. Units must be carried into the
answer, unless they cancel.
5.2 kg (2.9 m)
(18 s)(1.3 s) =
kg*m s2
0.64
4.8 g (23 s)
(18 s)(37 s) = g s
0.17

69. x + y = z x + y = z – y – y x = z – y Solve for x.
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,
x = z – y
leaving us with…

70. Numerical Example x – 24 = 13 x – 24 = 13 +24 +24 x = 37 Solve for x.
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

71. ( ) F = k x __ 1 k F = k x (or) F = k x k x = F k __ Solve for x.
x and k are connected by multiplication. Separate them using the opposite function: division.
(or)
F = k x k
The two k’s cancel on the right,
leaving us with…
x = F k __

72. ( ) Numerical Example 8 = 7 x __ 1 7 8 = 7 x (or) 8 = 7 x 7 x = 8 7 __
Solve for x.
8 = 7 x ( ) __ 1 7
8 = 7 x
x and 7 are connected by multiplication. Separate them using the opposite function: division.
(or)
8 = 7 x 7
The two 7’s cancel on the right,
leaving us with…
x = 8 7 __

73. ( ) ___ x BA = TR H BAH = xTR 1 TR ___ BAH = xTR ___ BAH TR x =
Solve for x.
___ x BA = TR H
One way to solve this is to cross-multiply.
BAH = xTR 1 TR ( )
___
Then, divide both sides by TR.
BAH = xTR
___
BAH TR
x =
The answer is…

74. ( ) ____ T1 P1V1 = P2V2 T2 1 ____ P1V1T2 = P2V2T1 T2 = P1V1 ______
Solve for T2, where…
P1 = 1.08 atm
P2 = 0.86 atm
V1 = 3.22 L
V2 = 1.43 L
T1 = 373 K
____ T1
P1V1 =
P2V2 T2 1
P1V1 ( )
____
P1V1T2 = P2V2T1
T2 =
P1V1
______
P2V2T1
T2 =
(1.08 atm)(3.22 L)
_____________________
(0.86 atm)(1.43 L)(373 K) =
130 K

75. You will be responsible for knowing these!
SI Prefixes
kilo- (k) 1000
deci- (d) 1/10
centi- (c) 1/100
milli- (m) 1/1000
Also,
1 mL = 1 cm3 and 1 L = 1 dm3
You will be responsible for knowing these!

76. Conversion Factors and Unit Cancellation

77. How many cm are in 1.32 meters?
equality:
1 m = 100 cm
(or 0.01 m = 1 cm)
conversion factors:
______
1 m
100 cm
______
1 m
100 cm or
1.32 m
1 m
100 cm
= cm
We use the idea of unit cancellation
to decide upon which one of the two
conversion factors we choose.

78. Again, the units must cancel.
How many m is 8.72 cm?
equality:
1 m = 100 cm
conversion factors:
______
1 m
100 cm
______
1 m
100 cm or
8.72 cm
1 m
100 cm
= m
Again, the units must cancel.

79. How many kilometers is 15,000 decimeters?
15,000 dm
10 dm
1 m
1,000 m
1 km
1.5 km =

80. How many seconds is 4.38 days?
____ ( ) ( )
_____ ( )
____
24 h
1 d
1 h
60 min
1 min
60 s
4.38 d
= 378,432 s
If we are accounting for significant figures, we would change this to…
3.78 x 105 s

81. 4. Convert 41.2 cm2 to mm2 Recall that… 1 cm = 10 mm ( )2 ( )2
( )2
( )2
41.2 cm2
1 cm2
102 mm2 =
4,120 mm2

82. SI-US Conversion Factors
Equality Conversion Factors
Length
2.54 cm
1 in
1 in
2.54 cm
2.54 cm = 1 in.
and
39.4 in
1 m
1 m
39.4 in.
1 m = 39.4 in.
and
Volume
946 mL
1 qt
1 qt
946 mL
946 mL = 1 qt
and
1.06 qt
1 L
1 L
1.06 qt
and
Dominoes Activity
1 L = 1.06 qt
Mass
453.6 g
1 lb
1 lb
453.6 g
453.6 g = 1 lb
and
2.20 lb
1 kg
1 kg
2.20 lb
1 kg = 2.20 lb
and

83. Simple Math with Conversion Factors

84. ( ) ( ) ______ ______ Find area of rectangle. A = L . W 4.6 cm
= (4.6 cm)(9.1 cm)
9.1 cm
= 42 cm 2
. cm
cm.cm ( )
______
100 cm
1 m
Convert to m2.
42 cm2 2
= m2 ( )
______
1 cm
10 mm
Convert to mm2.
42 cm2 2
= mm2

85. 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

86. ( ) ______ Convert to mm3. 1 cm 10 mm 2600 cm3 3 = 2,600,000 mm3
= x 106 mm3
mm and cm differ by a factor of……….
mm2 “ cm2 “ “ “ “ “ ……….
mm3 “ cm3 “ “ “ “ “ ………. 10
100
1000

87. Density  how tightly packed the particles are m V D Density =
Typical units:
g/cm3 for solids
g/mL for fluids
Glass: liquid or solid?
liquids
and gases

88. To find volume, use… 1.
a formula
V = p ∙ r2 ∙ h
V = l ∙ w ∙ h 2.
water displacement
V = ?
Vfinal
Vinitial
Vobject = Vfinal – Vinitial

89. Things that are “less dense” float in things that are “more dense.”
** Density of water =
1.0 g/mL = 1.0 g/cm3
Things that are “less dense” float
in things that are “more dense.”
(And things that are “more dense” sink
in things that are “less dense.”
D < 1 g/cm3
D > 1 g/cm3
D < 1 g/cm3
D < 1 g/cm3
The density of a liquid or solid is nearly constant,
no matter what the sample’s temperature
Density of gases is highly dependent on temperature

90. Ironwood Trees
Several different varieties of hardwood trees, having densities between 1.34 and 1.49 g/cm3
Most dense species is South African Ironwood (black ironwood)
Olea laurifolia
Found in Florida and
West Indies
D = 1.49 g/cm3

91. Will Bowling Balls sink or float in H2O?
If DBB > 1, it will sink
If DBB < 1, it will float
21.6 cm in diameter
Vsphere = 4/3 p r3
V = 4/3 p (10.8 cm)3 m V D
V = 5,276.7 cm3
m = D V
m = (1.00 g/cm3)( cm3)
m = g
Since the mass of a BB varies, let’s figure out at what mass it will sink v. float
…or 11.6 lbs

92. Density Calculations
1. A sample of lead (Pb) has mass
22.70 g and volume cm3. Find sample’s density. m V D =
2. Another sample of lead occupies 16.2 cm3
of space. Find sample’s mass. V
m = D V
= 184 g

93. Indiana Jones Density
Watch the famous opening scene to Indiana Jones and the Raiders of the Lost Ark
The “pure gold” idol has a density of 19.3 g/cm3. How much would it mass?
Indy replaces the idol with a bag of sand (density = 2.5 g/cm3). Why did he activate the booby trap? How much sand should he have used?
Did you see that toss at the end!? How much would the idol weigh in lbs? (2.2 lb per kg)
19,300 g
7,720 cm3 or 7.72 L!
42.5 lbs!

94. 3. A 119 g solid cylinder has radius 1.80 cm and height 1.50 cm. Find
sample’s density.
1.5 cm
1.8 cm m V D
V = p r2 h
= p (1.8 cm)2(1.5 cm) =
cm3 =

95. this object sink in water?m
8.2 cm
5.1 cm
4.7 cm
4. A 153 g rectangular solid
has edge lengths 8.20 cm,
5.10 cm, and 4.70 cm. Will
this object sink in water?
(Find the object’s density and compare it to water’s density.) m V D
V = l w h
= 8.20 cm (5.10 cm)(4.70 cm) =
cm3
= 0.778
< 1
No; it floats.

96. D5 D4 D3 D2 Galilean Thermometer Problem
On a cold morning, a teacher walks into a
cold classroom and notices that all bulbs
in the Galilean thermometer are huddled
in a group. Where are the bulbs? At the
top of the thermometer, at the bottom or elsewhere? D1
1. Bulbs have essentially fixed masses
and volumes. Therefore, each bulb
has a fixed density. D2 D3 D4
2. The surrounding liquid has a fixed
mass, but its volume is extremely
temperature-dependent. D5

97. Dliq D5 Vliq D4 D3 D2 3. The density of the liquid can be written as…
so…
…if the liquid is cold:
…but if it’s hot:
Dliq
mliq
mliq = =
Dliq
Vliq
Vliq
On a cold morning,
where are the bulbs?
AT THE TOP

98. Osmium 76Os

99. Basic Concepts in Chemistry

100. “what you started with”
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 started with”
differs from
“what you end up with”
reactants
products

101. Reactants
Products
carbon
dioxide
methane + oxygen  +
water
CH4(g) + 2
O2(g) 
CO2(g) +
H2O(g) 2 

102. Reactants
Products
sodium
hydroxide
sodium +
water 
hydrogen + 2
Na(s) + 2
H2O(l) 
H2(g) + 2
NaOH(aq) 

103. Law of Conservation of Mass:
2 Cu + H2O + CO2 + O2  CuCO3 + Cu(OH)2
Copper “patina” is a mixture of
copper(II) carbonate and copper(II) hydroxide.
It has a characteristic green color.
total mass total mass
of products of reactants =
Pmass = Rmass

104. Losing weight? Keeping the Law of onservation of mass in mind…
When you lose weight, where does it go?
Three ways, all of which involve excretion

105. A proposed organic synthesis of tetrahydrocannabinol (THC)
putting simpler substances together, usually in many steps, to make something more complex
A proposed organic synthesis of tetrahydrocannabinol (THC)