1. Chemistry

2. How did Chemistry Become a Science?

3. The Greeks believed there were four elements.
The Beginnings
early practical chemistry:
household goods, weapons,
soap, wine, basic medicine
The Greeks believed there
were four elements. ~ D D
___ D
___
earth air fire water

4. Timeline Greeks (Democratus ~450 BC) Discontinuous theory of matter
ALCHEMY
Issac Newton
( )
400 BC
300 AD
1000
2000
Greeks
(Aristotle ~350 BC))
Continuous
theory of matter
American
Independence
(1776)

5. Allegedly, this substance would turn cheap metals into gold.
Alchemy
In Europe,
alchemy was
the quest for the Philosopher’s Stone
(the elixir, the Sorcerer’s Stone).
Allegedly, this substance would turn
cheap metals into gold.

6. Alchemy Symbols
Alchemy Symbols

7. Alchemy (~500 – 1300 A.D.)
the quest for the
Philosopher’s Stone
It was supposed to change cheap metals into gold.
The Alchemist, by David Teniers
Alchemical symbols for substances…
. . .
. . .
SAND
IRON
GOLD
SILVER
COPPER
transmutation: changing one substance into another
In ordinary chemistry, we cannot transmute elements.

8. Contributions of alchemists: Information about elements
- the elements mercury, sulfur, and antimony were discovered
- properties of some elements
Develop lab apparatus / procedures / experimental techniques
- alchemists learned how to prepare acids.
- developed several alloys
- new glassware

9. Early Ideas on Elements
Robert Boyle stated...
A substance was an element unless it could be broken down to two or more simpler substances.
Air therefore could not be an element because it could be broken down in to many pure substances.
Robert Boyle

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

11. Areas of Chemistry Organic Inorganic Analytical Physical Biochemistry
The study of most carbon-containing compounds
The study of all substances not classified as organic,
mainly those compounds that do not contain carbon
The identification of the components and composition
of materials
The five areas of chemistry listed: organic, inorganic, analytical, physical and biochemistry are the main areas of chemistry.
Many people work as chemist in related fields – law, pharmaceutical, medical, agricultural, sales.
The study of the properties, changes, and relationships
between energy and matter
The study of substances and processes occurring in
living things

12. Government Regulation of Chemicals
…to protect the…
environment consumer worker
Consumer Product
Safety Commission,
USDA, BATF, FDA
OSHA
EPA

13. Chemistry and Manipulating Numerical Data

14. Graphs

15. Graphs Bar Graph Pie Graph Line Graph
Used to display information collected by counting
Pie Graph
Used to show how some fixed quantity is broken down into parts
Line Graph
Used to show trends or continuous change
GRAPHS
Each graph is used for a specific reason.

16. Elements of a “good” line graph
axes labeled, with units
use the available space
title
neat
Hopefully, students will realize this data makes no sense. As temperature increase – the volume of a gas increases.

17. How to read a graph 7 L ~4 L Interpolate - read between data points
What volume would the gas occupy at a temperature of 150 K?
Extrapolate - read data beyond data points
What volume would the gas occupy at a temperature of 260 K?
Which do you have more confidence in? Why?
7 L
(dependent variable)
Hopefully, students will realize this data makes no sense. As temperature increase – the volume of a gas increases.
~4 L
(independent variable)

18. Scientific Notation
We often use very small and very large numbers in chemistry.
Scientific notation is a method to express these numbers in a
manageable fashion.
Thus cm can be written 1 x 10-7 cm.
Lets see why…
Scientific notation expresses a number as the product of two
factors, the first falling between 1 and 10 and
the second being a power of 10.

19. 6.02 x 1023 Method to express really big or small numbers.
Format is Mantissa x Base Power
Decimal part of
original number
Decimal
you moved
6.02 x 1023
We just move the decimal point around.

20. Scientific Notation 5000 = 5 x 103 or 5 3 EE 5 x (10 x 10 x 10)
Numbers are written in the form M x 10n, where the factor
M is a number greater than or equal to 1 but less than 10 and
n is a whole number.
= 5 x or
5 x (10 x 10 x 10)
5 x 1000
5000
Numbers > one have a positive exponent.
Numbers < one have a negative exponent.
x 10n EE

21. Converting Numbers to Scientific Notation
2.205 x 10-5 1 2 3 4 5
In scientific notation, a number is separated into two parts.
The first part is a number between 1 and 10.
The second part is a power of ten.

22. 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 / 10 / 10 / 10
= 1.4 x 10-3

23. Change to standard form.
1.87 x 10–5 =
3.7 x 108 =
7.88 x 101 =
2.164 x 10–2 = . .
370,000,000
78.8

24. Change to scientific notation.
12,340 =
0.369 =
0.008 =
10,000,000 =
1.234 x 104
3.69 x 10–1
8 x 10–3
1 x 107

25. Essential Math of Chemistry
                                                                                                                                                      
Essential Math of Chemistry
“No human endeavor can be called science
if it can not be demonstrated mathematically.”
Leonardo da Vinci ( )

26. The Importance of Units
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)
(5.2 s)(37 s) = g s
0.57

27. Basic Algebra x + y = z x + y = z – y – y x = z – y
Solve the following 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,
x = z – y
leaving us with…

28. Basic Algebra 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

29. ( ) Basic Algebra F = k x __ 1 k F = k x (or) F = k x k x = F k __
Solve for x.
F = k x ( ) __ 1 k
F = k 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 left,
leaving us with…
x = F k __

30. ( ) Basic Algebra 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 __

31. ( ) Basic Algebra ___ x BA = TR H BAH = xTR 1 TR ___ BAH = xTR ___ BAH
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…

32. ( ) ____ T1 P1V1 = P2V2 T2 1 P1V1 ____ 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)
_____________________
(0.85 atm)(1.43 L)(373 K) =
130 K

33. 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?”

34. SI Prefixes kilo- 1000 deci- 1/10 centi- 1/100 milli- 1/1000
Also know…
1 mL = 1 cm3 and 1 L = 1 dm3

35. Conversion Factors and Unit Cancellation
Converting between two sets of units never changes the number of significant figures in a measurement. Remember, data are only as good as the original measurement, and no later manipulations can clean them up.

36. A physical quantity must include:
Number
+ Unit

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

38. Again, the units must cancel.
How many meters is 8.72 cm?
equality:
1 m = 100 cm
applicable conversion factors:
______
1 m
100 cm
______
1 m
100 cm or ( )
______
1 m
100 cm m
X m = 8.72 cm =
Again, the units must cancel.

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

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

41. Simple Math with Conversion Factors

42. Example Problem Measured dimensions of a rectangle:
length (L) = 9.70 cm
width (W) = 4.25 cm L W
Find area of rectangle.
A = L . W
= (9.70 cm)(4.25 cm) =
41.2 cm 2
. cm

43. ( ) ( ) ( ) ( ) Convert 41.2 cm2 to m2. ______ ______ ______ ______
X m2 = 41.2 cm2 =
0.412 m2
WRONG! =
0.412 cm.m
Recall that… 41.2 cm2 = 41.2 cm.cm ( )
______ ( )
______
X m2 = 41.2 cm.cm
100 cm
1 m
100 cm
1 m = m2 ( )
______
100 cm
1 m 2
X m2 = 41.2 cm2 = m2

44. 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) =
480 cm 3

45. Basic Concepts in Chemistry

46. any substance that takes part in, or occurs as a result of,
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.

47. a rearrangement of atoms such that
chemical reaction
a rearrangement of atoms such that
“what you end up with” products
differs from
“what you started with” reactants

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

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

50. Law of Conservation of Mass
total mass = total mass
of reactants of products
Rmass = Pmass

51. taking small molecules and putting them
Synthesis
taking small molecules and putting them
together, usually in many steps, to make
something more complex
Sunlight
Carbon
Dioxide
Oxygen
Glucose
Water
Photosynthesis
CO H2O O C6H12O6