1. Unit 1 Introduction to Chemistry

2. Safety

3. Basic Safety Rules #1 Rule: Use common sense. Others: No horseplay.
No unauthorized experiments.
Handle chemicals/glassware with respect.

4. Safety Features of the Lab
safety shower
fire blanket
fire extinguisher
eye wash
fume hood

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

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

7. 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

8. 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.

9. Science

10. 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

11. Science attempts to establish cause-effect relationships.

12. risk-benefit analysis weigh pros and cons before deciding
Because there are many considerations for each case, “50/50 thinking” rarely applies.

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

14. The Scientific Method

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

16. Observations are also called data.
Types of Data
Observations are also called data.
qualitative data quantitative data --
descriptions --
measurements
e.g.,
clear liquid
e.g.,
55 L or 83oC

17. 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

18. 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

19. Scientific Law vs. Scientific Theory
states what happens --
does not change --
never violated
-- e.g.,
law of gravity,
laws of conservation
theory:
-- e.g., --
tries to explain why or
how something happens
based on current evidence
Theory of Gravity,
Atomic Theory

20. 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)

22. Chemistry

23. 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

24. 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

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

26. 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.

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

28. What is Chemistry?
the study of matter
and its changes

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

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

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

32. 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

33. are affected by chemistry.
All fields of endeavor
are affected by chemistry.

34. Government Regulation of Chemicals
The government
regulates chemicals
to protect the…
worker
OSHA
environment
FDA
USDA
FAA
CPSC
EPA
consumer

36. Manipulating Numerical Data

37. Graphs

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

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

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

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

42. Essential Math of Chemistry

43. 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 = x 10 x 10 x 10
= x 103 =
= 1.4 x 10–3

44. 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
10,000,000 = 1 x 107
6.02 x 1023 =
602,000,000,000,000,000,000,000

45. Using the Exponent Key
EXP EE

46. 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 .

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

48. 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

49. 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

50. Essential Math of Chemistry

51. 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 kg (23 s)
(18 s)(37 s) = kg s
0.17

52. 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…

53. 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

54. ( ) 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 __

55. ( ) 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 __

56. ( ) ___ 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…

57. ( ) ____ 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) =
132 K

59. Conversion Factors and Unit Cancellation

60. 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

61. ( ) ______ 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 m
100 cm
1.32 m
= cm
We use the idea of unit cancellation
to decide upon which one of the two
conversion factors we choose.

62. 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 ( )
______
1 m
100 cm
8.72 cm
= m
Again, the units must cancel.

63. ( ) ( ) ____ ______ How many kilometers is 15,000 decimeters? 10 dm
1 km
15,000 dm
= km

64. 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

65. Simple Math with Conversion Factors

66. ( ) ( ) ______ ______ 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

67. 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

68. ( ) ______ 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

69. Basic Concepts in Chemistry

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

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

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

73. 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

74. Again, the units must cancel.
How many feet is inches?
equality:
1 ft = 12 in
applicable conversion factors:
______
1 ft
12 in
______
1 ft
12 in or ( )
____
1 ft
12 in
3.28 ft
X ft = in =
Again, the units must cancel.