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Welcome to CHEMISTRY !!!

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Title: Welcome to CHEMISTRY !!!


1
Welcome to CHEMISTRY !!!
  • An Observational Science
  • An Experimental Science
  • A Laboratory Science
  • An Interesting Science
  • An Important Science
  • A Hard Science

2
What Happened To The Balloon?
  • It was Whimpy and Broke!
  • It was fearful of all of the people!
  • Campbell scared it!
  • It got zapped by Klingons!
  • Hydrogen burns!

3
2H2 (g) O2 (g) 2 H2O (g) Energy
  • Hydrogen and oxygen are diatomic gases!
  • Water can be a gas!
  • ENERGY was given off!-- This is characteristic of
    an Exothermic Reaction!
  • This is a balanced chemical reaction!

4
CHEMISTRY
The Study of Matter and its Properties, the
Changes that Matter Undergoes, and the
Energy Associated with those Changes
5
Chemistry as the Central Science
Atmospheric Sciences
Physics
Oceanography
Medicine
Economics
Governments
Chemistry
People
Geology
Biology
Politics
Astronomy
Anthropology
6
Chemistry 142B Campbell / Callis
Text Chemistry - The Molecular Nature of Matter
and Change - By Martin Silberberg
Chapter 1 Keys to the Study of
Chemistry Chapter 2 The Components of
Matter Chapter 3 Stoichiometry Mole - Mass
Relationships in Chemical
Systems Chapter 4 The Major Classes of
Chemical Reactions Chapter 5 Gases and the
Kinetic - Molecular Theory Chapter 6
Thermochemistry Energy Flow and Chemical
Change Chapter 7 Quantum Theory
and Atomic Structure Chapter 8 Electron
Configuration and Chemical Periodicity
7
Chemistry Homework !!!
Chemistry is not a spectator sport, you must
become involved, and that means that you must do
homework!
Linus Pauling - 1967
8
CHEMISTRY 142B SYLLABUS
INSTRUCTOR (1) Professor C. T. Campbell
(campbell_at_chem.washington.edu).
Telephone616-6085, Office Hours Mon.
1030-1130, Weds. 230-330 in 227
Bagley.INSTRUCTOR (2) Professor J. B. Callis
(callis_at_cpac.washington.edu) Telephone
543-1208, Office Hours Wed. 230 - 420, 204
Bagley HallTEXTS Silberberg, Chemistry, The
Molecular Nature of Matter and Change, Second
Edition, 2000, McGraw-Hill (required for
lecture) Chemistry 142 Laboratory Manual,
available at the Copy Center, Odegaard Library
(required for lab). OPTIONAL Weberg,
Student Study Guide to Accompany Chemistry, The
Molecular Nature of Matter and Change, 1996,
Moseby. On reserve Chemistry Library.CHEMISTRY
STUDY CENTER - BAG 330 M - Th 9 a.m. - 6 p.m, F
9 am - 2 pm. Work with / learn from fellow
Chem. 142 students. Receive help from the TA's.
27 computers with helpful general chemistry
programs. Photocopy machine is available at 10
cents per copy.LAB GROUP NUMBERS You are
in Gp. 1 if you are in subsections D, G, H, I,
J, K or L Gp. 2 if you are in subsections A, B,
C, E or F.COURSE SCHEDULE
9
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10
POLICIES AND PROCEDURESLECTURES Read the
material to be covered prior to the lecture.
QUIZ SECTIONS Help quiz.EXPERIMENTAL LABS
Pick up your C142 Lab Manual well in advance and
read it up through 1st expt. carefully. LAB
PRELIMS before you enter the laboratory for
each new experiment (1) complete that labs
Preliminary Exercise, (2) Fill out Purpose and
Procedure. LAB REPORTS For all 4 of the
labs, complete all calculations and tabulate your
results in lab manual in lab. For one of the
labs write a formal lab report (due the next
week in lab).EXAMS - Most of the questions on
the exams will be similar to homework problems.
FINAL EXAM - 1st half material presented
since Midterm Exam 2. 2nd half cumulative
review of all lecture material in Ch.
1-8.REGRADING OF HOMEWORK, LAB REPORTS AND
EXAMS- LATE POLICY - and MAKE-UP WORK
COURSE GRADING - 2 midterm exams (1 hr. each,
100 pts. each) 34 Quizzes / homework
(lowest HW and quiz score dropped) 17
Informal laboratory reports (4) 12
Formal laboratory report 4 Final
exam (2 hr.)
33 TOTAL 100
11
Safety There is an element of hazard in any
laboratory course. You are required to follow the
safety rules as outlined in your laboratory
manual. In particular you are required to wear
approved safety goggles during all experiments.
Proper clothing must be worn at all times.
Unnecessarily-exposed skin is at risk from
accidental spills, therefore shorts, short
skirts, or open-toed shoes are not allowed in the
laboratory. In order to comply with this policy,
I suggest that you keep a pair of jogging pants
and sneakers in one of the hall lockers, along
with safety goggles. The lab is not a good place
to wear your favorite clothes. Long hair should
be tied back. You may buy goggles and notebooks
at the University Book Store.
12
Chapter 1 Keys to the Study of Chemistry
First Read Appendix A at back of book Math
review for math needed in Chem 142. 1.1 Some
Fundamental Definitions 1.2 Chemical Arts and the
Origins of Modern Chemistry 1.3 The
Scientific Approach Developing a Model 1.4
Chemical Problem Solving 1.5 Measurement in
Scientific Study 1.6 Uncertainty in Measurement
Significant Figures
13
Definitions-I
Matter - The stuff of the universe books,
planets, trees, professors -
anything that has mass and
volume. Composition - The types and amounts of
simpler substances that make up a
sample of matter. Properties - The
characteristics that give each
substance a unique identity. Physical
Properties - are those the substance shows by
itself, without interacting with
another substance ( color,
melting point, boiling point,density, etc.)
Chemical Properties - are those that the
substance shows as it interacts
with, or transforms into, other
substances (flammability, corrosiveness, etc.)
14
Fig 1.1 (P. 3) The distinction between
physical and
chemical change.
Solid and Liquid water have the same
chemical composition.
15
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16
STATES OF MATTER -and The World around US
  • SOLID - The Earth
  • LIQUID - Water
  • GAS - The Atmosphere

17
Fig1.2
18
demos
19
Energy Involved in Phase Changes
Liberates Energy
Gas
Boiling
Condensation
Liquid
Melting
Freezing
Solid
Requires Energy
20
Definitions - II
Energy - The capacity to do work! Potential
Energy - The energy due to the position
of the object.Or Energy
from a chemical
reaction. Kinetic Energy - The energy due to
the motion of the
object ( 1/2 mass x velocity2)
21
Fig. 1.3
22
Fig.1.6
23
Fig.1.7
24
Aspects of The Scientific Approach 1.
Quantitative, reproducible measurements. 2.
Theories that explain these, and thus hope to
reveal the mysteries of how nature works. 3.
Testing of these theories (esp. convincing when
making accurate predictions of new
behavior). Curiosity driven desire to
understand how nature works (basic or
fundamental research) or Application driven
desire to improve a product or process or to
cure a problem (applied research)
25
Units Used in Calculations
Length A car is 12 feet long, not 12 long !
A person is 6
feet tall, not 6 tall !
Area A carpet measuring 3 feet(ft) by 4 ft has
an area of (3 ft)x(4 ft) (
3 x 4 )( ft x ft ) 12 ft2
Speed and Distance A car traveling 350
miles(mi) in
7 hours(hr) has a speed of In 3 hours the
car travels
26
Units Used in Calculations
Length A car is 12 feet long, not 12 long !
A person is 6
feet tall, not 6 tall !
Area A carpet measuring 3 feet(ft) by 4 ft has
an area of (3 ft)x(4 ft) (
3 x 4 )( ft x ft ) 12 ft2
Speed and Distance A car traveling 350
miles(mi) in
7 hours(hr) has a speed of 350 mi / 7 hr
(350/7) x (mi/hr) 50 mi/hr In 3 hours the
car travels (3 hr) x (50 mi/hr) 150 mi
27
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28
Derived SI Units
Quantity Definition of Quantity
SI unit
Area Length squared
m2 Volume
Length cubed
m3 Density Mass per unit
volume kg/m3 Speed
Distance traveled per unit time
m/s Acceleration Speed
changed per unit time
m/s2 Force Mass times
acceleration of object kg m/s2

( newton,
N) Pressure Force per unit area
kg/(ms2)

( pascal,
Pa) Energy Force times distance
traveled kg m2/s2

( joule, J)
29
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30
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31
How to Solve Chemistry Problems
1) Problem States all of the information needed
to solve the Problem. 2)
Plan Clarify the known and unknown.
Suggest the steps needed to find the
solution. Develop
a roadmap solution. 3)Solution Calculations
appear in the same order as outlined. 4) Check
Is the result what you expect or at least in the
same order of magnitude! 5)
Comment Additional information as needed.
32
Conversion Factors Unity Factors - I
Equivalent factors can be turned into conversion
factors by dividing one side into the other!
1 mile 5280 ft or 1 1 mile / 5280 ft
5280 ft / 1 mi
1 in 2.54 cm or 1

In converting one set of units for another, the
one desired is on top in the conversion factor,
and the old one is canceled out!
convert 29,141 ft into miles!
33
Conversion Factors Unity Factors - I
Equivalent factors can be turned into conversion
factors by dividing one side into the other!
1 mile 5280 ft or 1 1 mile / 5280 ft
5280 ft / 1 mi
1 in 2.54 cm or 1 1 in / 2.54 cm
2.54 cm / 1 in
In converting one set of units for another, the
one desired is on top in the conversion factor,
and the old one is canceled out!
convert 29,141 ft into miles!
29,141 ft x 1 mi / 5280 ft 5. 519 mi
34
Conversion Factors - II
1.61 km 1 mi or 1
Convert 5.519 miles in to kilometers
Conversions in the metric system are easy, as 1
km 1000 m and 1 meter (m) 100 centimeters
(cm) and 1 cm 10
millimeters (mm).
Ex. Convert 8.89 km into cm and mm
35
Conversion Factors - II
1.61 km 1 mi or 1 1.61 km / 1 mi
Convert 5.519 miles in to kilometers
5.519 mi x 1.61 km / mi 8.89 km
Conversions in the metric system are easy, as 1
km 1000 m and 1 meter (m) 100
centimeters(cm)
and 1 cm 10 millimeters(mm).
Ex. Convert 8.89 km into cm and mm
8.89 km x 1000m / 1 km 8890 m 8890 m x
100 cm / m 889000 cm
36
Conversion Factors - III
  • Multiple conversion factors!
  • Convert 3.56 lbs/hr into units of milligrams/sec!

37
Conversion Factors - III
  • Multiple conversion factors!
  • Convert 3.56 lbs/hr into units of milligrams/sec!
  • 3.56 lbs/hr x (1kg/2.205 lbs) x(1000g/1kg) x
  • (1000mg/1g) x (1hr/60 min) x (1min/60 sec)

  • 448 mg/sec

38
Fig. 1.9
cm3 mL
Liter L dm3
m3
39
Fig. 1.10
40
Conversion Factors - IVmetric volume to liters
  • 1.35 x 109 km3 volume of worlds oceans.
  • 1 Liter 1 L 1 dm3
  • How many liters of water are in the oceans?
  • conversion factors 1 km 1000 m
  • 1 L 1 dm3 10-3 m3 or 1000 L
    1 m3

41
Conversion Factors - IVmetric volume to liters
  • 1.35 x 109 km3 volume of worlds oceans.
  • 1 Liter 1 L 1 dm3
  • How many liters of water are in the oceans?
  • conversion factors 1 km 1000 m
  • 1 L 1 dm3 10-3 m3 or 1000 L
    1 m3
  • 1.35 x 109 km3 x (103 m/1 km )3 x ( 103 L/m3)
  • 1.35 x 1021 liters

42
Calculate the mass of 1.00 ft3 of Lead
(density11.3 g/ cm3)?
Conversion Factors - V
  • 1 cm3 of Pb 11.3 g of Pb so
    1 (11.3 g of Pb)/(1 cm3 of Pb)
    11.3 g/cm3

43
Calculate the mass of 1.00 ft3 of Lead
(density11.3 g/ cm3)?
Conversion Factors - V
  • 1 cm3 of Pb 11.3 g of Pb so
    1 (11.3 g of Pb)/(1 cm3 of Pb)
    11.3 g/cm3
  • 1.00 ft3 x (12 in/ft)3 x (2.54 cm/in)3

  • 28,316.84659 cm3
  • 2.83 x 104 cm3 x 11.3 g/cm3 319,790.0000 g
  • Ans. 3.20 x 105 g 3.20 x 102 kg

44
Fig1.11
45
Like Sample Problem 1.3 (p20)
The Volume of an irregularly shaped solid can be
determined from the volume of water it displaces.
A graduated cylinder contains 245.0 mL water.
When a small piece of Pyite, an ore of Iron, is
submerged in the water, the volume increases
to 315.8 mL . What is the volume of the piece of
Pyrite in cm3 and in liters.
Vol (mL )
Vol (cm3) Vol (liters)
46
Like Sample Problem 1.3 (p20)
The Volume of an irregularly shaped solid can be
determined from the volume of water it displaces.
A graduated cylinder contains 245.0 mL water.
When a small piece of Pyite, an ore of Iron, is
submerged in the water, the volume increases
to 315.8 mL . What is the volume of the piece of
Pyrite in cm3 and in liters.
Vol (mL ) 315.8 mL - 245.0 mL 70.80 mL
Vol (cm3) 70.80 mL x 1 cm3/ 1 mL 70.80
cm3 Vol (liters) 70.80 mL x 10 -3liters / mL
7.08 x 10 -2 liters
47
Sample Problem 1.5 (p 23) - I
Lithium (Li) is a soft, gray solid that has the
lowest density of any metal. If a slab of Li
weighs 1.49 x 103 mg and has sides that measure
20.9 mm by 11.1 mm by 12.0 mm, what is the
density of Li in g/ cm3 ?
48
Sample Problem 1.5 - II
Mass (g) of Li 1.49 x 103 mg Length (cm) of
one side 20.9 mm Similarly, the other side
lengths are Volume (cm3) Density
mass/volume Density of Li
49
Sample Problem 1.5 - II
1 g
Mass (g) of Li 1.49 x 103 mg x
1.49 g Length (cm) of one side 20.9 mm x
1cm / 10 mm 2.09 cm Similarly, the other side
lengths are 1.11 cm and 1.20 cm Volume (cm3)
2.09 cm x 1.11 cm x 1.20 cm 2.78 cm3 Density
mass/volume Density of Li
0.536 g/cm3
103 mg
1.49 g
2.78 cm3
50
Like Sample Problem 1. 5 - Density of a Metal
Problem Cesium is the most reactive metal in the
periodic table. What is its density if a
3.4969 kg cube of Cs has sides of 125.00 mm
each? Plan Calculate the volume from the
dimensions of the cube, and calculate the
density from the mass and volume. Solution
length 125.00 mm
mass 3.4969 kg
Volume
mass
density
volume
51
Like Sample Problem 1. 5 - Density of a Metal
Problem Cesium is the most reactive metal in the
periodic table. What is its density if a
3.4969 kg cube of Cs has sides of 125.00 mm
each? Plan Calculate the volume from the
dimensions of the cube, and calculate the
density from the mass and volume. Solution
length 125.00 mm 12.500 cm
mass 3.4969 kg x 1000g/kg 3,496.9 g
Volume (length)3 (12.500 cm)3 1,953.125 cm3
mass 3496.9 g
density
1.7904 g/cm3
volume 1,953.125 cm3
52
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53
Archemedies Principle Problem
Problem Calculate the density of an irregulaly
shaped metal object that has a mass of 567.85
g if, when it is placed into a 2.00 liter
graduated cylinder containing 900.00 mL of
water, the final volume of the water in the
cylinder is 1,277.56 mL ? Plan Calculate the
volume from the different volume readings,
and calculate the density using the mass that
was given. Solution
Volume
mass
Density
volume
54
Archemedies Principle Problem
Problem Calculate the density of an irregulaly
shaped metal object that has a mass of 567.85
g if, when it is placed into a 2.00 liter
graduated cylinder containing 900.00 mL of
water, the final volume of the water in the
cylinder is 1,277.56 mL ? Plan Calculate the
volume from the different volume readings,
and calculate the density using the mass that
was given. Solution
Volume 1,277.56 mL - 900.00 mL 377.56 mL
mass 567.85 g
Density
1. 50 g / mL
volume 377.56 mL
55
Definitions - Mass Weight
Mass - The quantity of matter an object contains
kilogram - ( kg ) - the SI base unit of mass, is
a platinum -
iridium cylinder kept in
Paris as a standard!
Weight - depends upon an objects mass and the
strength of the gravitational
field pulling on it.
56
Sample Problem Computer Chips
Future computers might use memory bytes which
require an area of a square with 0.25 mm sides.
How many bytes could be put on a 1 in x 1 in
computer chip? If each byte required that 25
of its area to be coated with a gold film 10 nm
thick, what mass of gold would be needed to make
one chip?
Mass (g) of gold
57
Sample Problem Computer Chips
Future computers might use memory bytes which
require an area of a square with 0.25 mm sides.
How many bytes could be put on a 1 in x 1 in
computer chip? If each byte required that 25
of its area to be coated with a gold film 10 nm
thick, what mass of gold would be needed to make
one chip?
Mass (g) of gold
Total area / area of byte
Density Tab.1.5 gold 19.5 g/cm3
Gold area per byte x No. bytes
Area x thickness
58
Sample Problem Chips, soln.
Area of byte No. of bytes 1 in.2/chip Gold
area on a byte Gold area on chip
59
Sample Problem Chips, soln.
Area of byte 0.25 x 10-6 m x 0.25 x 10-6 m
6.25 x 10-14 m2 x (100 cm/m)2 6.25 x
10-10 cm2 /byte No. of bytes 1 in.2/chip
x (2.54 cm/in)2 / (6.25 x 10-10cm2/byte)
1.03 x
1010 bytes/chip Gold area on a byte (6.25 x
10-10 cm2 /byte)(0.25 cm2 gold/cm2 of
chip) 1.56 x 10-10 cm2 gold / byte Gold area
on chip (1.56 x 10-10 cm2 gold / byte)x(1.03
x 1010 bytes/chip) 1.61 cm2 gold / chip
60
Sample Problem Chips, soln. cont.
Gold volume on chip Density of gold 19.3
g/cm3 from Table 1.5 Mass of gold
61
Sample Problem Chips, soln. cont.
Gold volume on chip (1.61 cm2)x(10 nm) x
(10-7 cm/nm) 1.61x10-6 cm3 gold Density of
gold 19.3 g/cm3 from Table 1.5 Mass of gold
(1.61x10-6 cm3 gold)x(19.3 g gold/cm3 gold)
3.1x10-5 g gold 31 mg gold
62
Fig.1.12
63
Fig.1.13
64
Temperature Scales and Interconversions
Kelvin ( K ) - The Absolute temperature scale
begins at absolute zero
and only has positive values.
Celsius ( oC ) - The temperature scale used by
science, formally
called centigrade and most
commonly used scale around the world,
water freezes at 0oC, and boils
at 100oC.
Fahrenheit ( oF ) - Commonly used scale in
America for our
weather reports, water freezes at 32oF,
and boils at 212oF.
T (in K) T (in oC) 273.15 T (in oC) T (in
K) - 273.15
T (in oF) 9/5 T (in oC) 32 T (in oC) T
(in oF) - 32 5/9
65
Temperature Conversions
The boiling point of Liquid Nitrogen is -195.8
oC, what is the temperature in Kelvin and
degrees Fahrenheit?
T (in K) T (in oC) 273.15 T (in K)
T (in oF) 9/5 T (in oC) 32 T (in oF)
The normal body temperature is 98.6oF, what is it
in Kelvin and degrees Celsius?
T (in oC) T (in oF) - 32 5/9 T (in oC)
T (in K) T (in oC) 273.15 T (in K)
66
Temperature Conversions
The boiling point of Liquid Nitrogen is - 195.8
oC, what is the temperature in Kelvin and
degrees Fahrenheit?
T (in K) T (in oC) 273.15 T (in K) -195.8
273.15 77.35 K 77.4 K
T (in oF) 9/5 T (in oC) 32 T (in oF) 9/5 (
-195.8oC) 32 -320.4 oF
The normal body temperature is 98.6oF, what is it
in Kelvin and degrees Celsius?
T (in oC) T (in oF) - 32 5/9 T (in oC)
98.6oF - 32 5/9 37.0 oC
T (in K) T (in oC) 273.15 T (in K) 37.0 oC
273.15 310.2
67
Fig1.15
68
Fig. 1.16
69
Precision and Accuracy Errors in
Scientific Measurements
Precision - Refers to reproducibility or How
close the measurements are to
each other! Accuracy - Refers to how close a
measurement is to the real
value! Systematic error - produces values that
are either all higher
or all lower than the actual value. Random
Error - in the absence of systematic error,
produces some
values that are higher and some that
are lower than the actual value.
70
Fig. 1.17
71
Rules for Determining Which Digits Are
Significant
All digits are significant, except zeros that are
used only to position the decimal point.
1. Make sure that the measured quantity has a
decimal point. 2. Start at the left of the number
and move right until you reach the first
nonzero digit. 3. Count that digit and every
digit to its right as significant. Zeros that end
a number and lie either after or before the
decimal point are significant thus 1.030 mL
has four significant figures, and 5300. L has
four significant figures also. Numbers such as
5300 L have 2 sig. figs., but 5.30x103 L has 3.
A terminal decimal point is often used
to clearify the situation, but scientific
notation is clearer (best)!
72
Examples of Significant Digits in Numbers
Number - Sig digits Number
- Sig digits
0.0050 L two 1.34000 x 107
nm six 18.00 g four
5600 ng two 0.00012 kg
two 87,000 L
two 83.0001 L five
78,002.3 ng six 0.006002 g
four 0.000007800 g
four 875,000 oz three 1.089 x
10 -6L four 30,000 kg one
0.0000010048 oz five 5.0000 m3
five 6.67000 kg
six 23,001.00 lbs seven 2.70879000
mL nine 0.000108 g three
1.0008000 kg eight 1,470,000 L
three 1,000,000,000 g one
73
Rules for Significant Figures in answers
1. For multiplication and division. The number
with the least certainty limits the certainty of
the result. therefore, the answer contains the
same number of significant figures as there are
in the measurement with the fewest significant
figures. Multiply the following numbers
9.2 cm x 6.8 cm x 0.3744 cm 23.4225 cm3 23 cm3
2. For addition and subtraction. The answer has
the same number of decimal places as there are
in the measurement with the fewest decimal
places. Example, adding two volumes 83.5 mL
23.28 mL 106.78 mL 106.8 mL Example
subtracting two volumes 865.9 mL - 2.8121393
mL 863.0878607 mL 863.1 mL
74
Rules for Rounding off numbers
1. If the digit removed is more than 5, the
preceding number increases by 1 5.379 rounds
to 5.38 if three significant figures are retained
and to 5.4 if two significant figures are
retained. 2. If the digit removed is less than 5,
the preceding number is unchanged 0.2413
rounds to 0.241 if three significant figures are
retained and to 0.24 if two significant figures
are retained. 3.If the digit removed is 5, the
preceding number increases by 1 if it is odd and
remains unchanged if it is even 17.75 rounds to
17.8, but 17.65 rounds to 17.6. If the 5 is
followed only by zeros, rule 3 is followed if
the 5 is followed by nonzeros, rule 1 is
followed 17.6500 rounds to 17.6, but 17.6513
rounds to 17.7 4. Be sure to carry two or more
additional significant figures through a
multistep calculation and round off only the
final answer. (In sample problems and follow-up
problems, we round off intermediate steps of a
calculation to show the correct number of
significant figures.
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