24
CHEM 111 Fall 2017 Table of Contents (italicized entries indicate worksheets and extra practice problems) Periodic Table Calculator usage in General Chemistry Algebra worksheet (and answers) Chapter 0 notes Significant figures worksheet (and answers) Unit simplification worksheet (and answers) Chapter 1 notes 1A 8A 1 H 1.00794 2A 3A 4A 5A 6A 7A 2 He 4.00260 3 Li 6.941 4 Be 9.01218 <–––––– <–––––– <–––––– Atomic number Elemental symbol Atomic mass 5 B 10.811 6 C 12.0107 7 N 14.0067 8 O 15.9994 9 F 18.99840 10 Ne 20.1797 11 Na 22.98977 12 Mg 24.305 3B 4B 5B 6B 7B <------------8B -----------> 1B 2B 13 Al 26.98154 14 Si 28.0855 15 P 30.97376 16 S 32.066 17 Cl 35.4527 18 Ar 39.948 19 K 39.0983 20 Ca 40.078 21 Sc 44.9556 22 Ti 47.88 23 V 50.9415 24 Cr 51.994 25 Mn 54.938 26 Fe 55.847 27 Co 59.9332 28 Ni 58.6934 29 Cu 63.546 30 Zn 65.39 31 Ga 69.723 32 Ge 72.61 33 As 74.9216 34 Se 78.96 35 Br 79.904 36 Kr 83.80 37 Rb 85.4678 38 Sr 87.62 39 Y 88.9059 40 Zr 91.224 41 Nb 92.9064 42 Mo 95.94 43 Tc (98) 44 Ru 101.07 45 Rh 102.9055 46 Pd 105.42 47 Ag 107.868 48 Cd 112.41 49 In 114.82 50 Sn 118.710 51 Sb 121.757 52 Te 127.60 53 I 126.9045 54 Xe 131.29 55 Cs 132.9045 56 Ba 137.33 57 La 138.9055 72 Hf 178.49 73 Ta 180.9479 74 W 183.85 75 Re 186.207 76 Os 190.2 77 Ir 192.22 78 Pt 195.08 79 Au 196.966 80 Hg 200.59 81 Tl 204.383 82 Pb 207.2 83 Bi 208.98 84 Po (209) 85 At (210) 86 Rn (222) 87 Fr (223) 88 Ra 226.0254 89 Ac (227) 104 Rf (265) 105 Db (268) 106 Sg (271) 107 Bh (272) 108 Hs (270) 109 Mt (276) 110 Ds (281) 111 Rg (280) 112 Cn (285) 113 Nh (285) 114 Fl (289) 115 Mc (288) 116 Lv (293) 117 Ts (294) 118 Og (294) 58 Ce 140.12 59 Pr 140.9077 60 Nd 144.24 61 Pm (145) 62 Sm 150.36 63 Eu 151.965 64 Gd 157.25 65 Tb 158.9253 66 Dy 162.50 67 Ho 164.9303 68 Er 167.26 69 Tm 168.9342 70 Yb 173.04 71 Lu 174.967 90 Th 232.0381 91 Pa 231.0359 92 U 238.029 93 Np 237.0482 94 Pu (244) 95 Am (243) 96 Cm (247) 97 Bk (247) 98 Cf (251) 99 Es (252) 100 Fm (257) 101 Md (258) 102 No (259) 103 Lr (262)

Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

  • Upload
    vancong

  • View
    259

  • Download
    3

Embed Size (px)

Citation preview

Page 1: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

CHEM 111 Fall 2017

Table of Contents

(italicized entries indicate worksheets and extra practice problems)

Periodic Table

Calculator usage in General Chemistry

Algebra worksheet (and answers)

Chapter 0 notes

Significant figures worksheet (and answers)

Unit simplification worksheet (and answers)

Chapter 1 notes

1A 8A

1

H

1.00794

2A

3A

4A

5A

6A

7A

2

He

4.00260

3

Li

6.941

4

Be

9.01218

<––––––

<––––––

<––––––

Atomic number

Elemental symbol

Atomic mass

5

B

10.811

6

C

12.0107

7

N

14.0067

8

O

15.9994

9

F

18.99840

10

Ne

20.1797

11

Na

22.98977

12

Mg

24.305

3B

4B

5B

6B

7B

<------------8B ----------->

1B

2B

13

Al

26.98154

14

Si

28.0855

15

P

30.97376

16

S

32.066

17

Cl

35.4527

18

Ar

39.948

19

K

39.0983

20

Ca

40.078

21

Sc

44.9556

22

Ti

47.88

23

V

50.9415

24

Cr

51.994

25

Mn

54.938

26

Fe

55.847

27

Co

59.9332

28

Ni

58.6934

29

Cu

63.546

30

Zn

65.39

31

Ga

69.723

32

Ge

72.61

33

As

74.9216

34

Se

78.96

35

Br

79.904

36

Kr

83.80

37

Rb

85.4678

38

Sr

87.62

39

Y

88.9059

40

Zr

91.224

41

Nb

92.9064

42

Mo

95.94

43

Tc

(98)

44

Ru

101.07

45

Rh

102.9055

46

Pd

105.42

47

Ag

107.868

48

Cd

112.41

49

In

114.82

50

Sn

118.710

51

Sb

121.757

52

Te

127.60

53

I

126.9045

54

Xe

131.29

55

Cs

132.9045

56

Ba

137.33

57

La

138.9055

72

Hf

178.49

73

Ta

180.9479

74

W

183.85

75

Re

186.207

76

Os

190.2

77

Ir

192.22

78

Pt

195.08

79

Au

196.966

80

Hg

200.59

81

Tl

204.383

82

Pb

207.2

83

Bi

208.98

84

Po

(209)

85

At

(210)

86

Rn

(222)

87

Fr

(223)

88

Ra

226.0254

89

Ac

(227)

104

Rf

(265)

105

Db

(268)

106

Sg

(271)

107

Bh

(272)

108

Hs

(270)

109

Mt

(276)

110

Ds

(281)

111

Rg

(280)

112

Cn

(285)

113

Nh

(285)

114

Fl

(289)

115

Mc

(288)

116

Lv

(293)

117

Ts

(294)

118

Og

(294)

58

Ce

140.12

59

Pr

140.9077

60

Nd

144.24

61

Pm

(145)

62

Sm

150.36

63

Eu

151.965

64

Gd

157.25

65

Tb

158.9253

66

Dy

162.50

67

Ho

164.9303

68

Er

167.26

69

Tm

168.9342

70

Yb

173.04

71

Lu

174.967

90

Th

232.0381

91

Pa

231.0359

92

U

238.029

93

Np

237.0482

94

Pu

(244)

95

Am

(243)

96

Cm

(247)

97

Bk

(247)

98

Cf

(251)

99

Es

(252)

100

Fm

(257)

101

Md

(258)

102

No

(259)

103

Lr

(262)

Page 2: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

Calculators in General Chemistry

During exams in this class you will use only CASIO fx-260solar calculators. These are simple, scientific

calculators that will be more than sufficient to perform any calculations you will encounter in general

chemistry. Below are images of the two models of calculators (light keys and dark keys):

In the display of each is the number 6.626 10-34. Notice how the exponential numbers (10-34) leave out

the “10”—this part is assumed. So how do you input an exponential value into one of these calculators?

Use the EXP key (see the black arrow in the figures below).

Page 3: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

If you want to use the number 6.626 10-34 in a calculation, you simply type 6.626 34 . The

means that you will raise 10 to some power. Notice how you would type in 109 or 1 109. If you want to

type in this number you would type 1 9. If you type 10 9 the calculator would translate this as

10 109, which would be 1010—your calculation would be off by a whole order of magnitude!!

Lastly, here are some displays of numbers from a typical calculation (1.92697736 1025). The Casio

returns 10 digits, plus the power of 10. Each calculator actually keeps more digits in its memory than is

displayed on the screen. In general chemistry, 10 figures will be more than enough digits for your

calculations.

Although these calculators are simple, they are powerful, too. They have

1. memory functions,

2. a way to retype a number if you put in a wrong digit,

3. take the reciprocal of a number,

4. calculate square roots and cube roots quickly, and

5. nested functions (i.e., use parentheses to separate parts of a calculation).

EXP +/- EXP

EXP EXP

1. Hit the SHIFT key, then MR to

put the number to the memory. Hit

MR to recall the number from memory

2. Hit this arrow

key to backspace

4b. Hit SHIFT,

then +/- to take

the cube root

4a. To take the square

root, hit the SHIFT key,

followed by x2

5. These keys allow you to perform

functions in parentheses

3. Hit SHIFT and the ---)] key to take

the reciprocal of a number

Page 4: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

Algebra basics review sheet

Solve each of the following for x (that is, provide an answer where x = <number>). Do not use a calculator.

If you cannot easily work the problems on this sheet—WITHOUT A CALCULATOR, you most likely do not have the math

skills necessary for successful completion of this course. It is strongly recommended that you take more math to boost those

skills, then enroll in general chemistry.

1. 5.6 = 1.6x + 2

2. x

1612

3. 5.49

5)32(

x

4. (1000)(4.022) = (25.00)(x)

5. –4.33 – x = -2.55

6. x = 15 × 3 + 12 – 2 × 3 + 2

16

4

12 – 6 × 6 + 7

7. 50100

78 x

8. 41

x

9.

5.5

11

x

10. 123

34 xx

Algebra answers:

1. 2.25

2. 1.33333

3. 40.1

4. 160.88

5. -1.78

6. 33

7. 39

8. 0.25 (or 4

1 )

9. 5.5

10.

17

6

Page 5: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

Chapter 0 page 1 of 8

CHEM 111-Chapter 0

Chemical Tools: Experimentation and

Measurement

Chapter 0 Problems: 1-55, 58-83, 85-91, 92a

Is chemistry a:

(a) cult?

(b) science?

(c) religion?

(d) passing fad?

How do we define chemistry?

The Scientific Method

1st step-make an observation

2nd step-form a hypothesis

3rd step-conduct an experiment

If experimental conclusions don't match the hypothesis, which option should you choose?

(1) reject hypothesis or (2) reject experimental data

Theory: Complex hypothesis or set(s) of hypotheses/laws that have been repeatedly tested and not

shown to be wrong. Differs from a hypothesis because it is a broad ranging explanation (explains a

broad set of phenomena)

Science: A way of knowing about the physical universe (as opposed to other ways of "knowing”, eg.

belief, intuition). Utilizes processes of testing and experimentation to support or reject explanations

(hypotheses and theories) and descriptions of phenomena in the physical universe.

Page 6: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

Chapter 0 page 2 of 8

Measurements (Numbers and Units)

To write large and small numbers we will use scientific notation (#.## × 10x)

EX. 425,000 can be written as:

Another way to express very large and very small quantities is to use prefixes with the metric system

Table of Metric Prefixes

Prefix Symbol Value Example tera- T 1012 1,000,000,000,000 trillion 1 terameter (1 Tm) = 1012 m

giga- G 109 1,000,000,000 billion 1 gigameter (1 Gm) = 109 m

mega- M 106 1,000,000 million 1 megagram (1Mg) = 106 g

kilo- k 103 1,000 thousand 1 kilogram (1 kg) = 103 g

hecto- h 102 100 hundred 1 hectogram (1 hg) = 100 g

deka- da 101 10 ten 1 dekaliter (1 daL) = 10 L

-- -- -- -- -- --

deci- d 10-1 0.1 tenths 1 deciliter (1 dL) = 0.1 L

centi- c 10-2 0.01 hundredths 1 centiliter (1 cL) = 0.01 L

milli- m 10-3 0.001 thousandths 1 milliliter (1 mL) = 0.001 L

micro- μ 10-6 0.000 001 millionths 1 micrometer (1 μm) = 10-6 m

nano- n 10-9 0.000 000 001 billionths 1 nanometer (1 nm) = 10-9 m

pico- p 10-12 0.000 000 000 001 trillionths 1 picometer (1 pm) = 10-12 m

femto- f 10-15 0.000 000 000 000 001 quadrillionths 1 femtosecond (1 fs) = 10-15 s

Note that some abbreviations are capitalized while others are not.

Capitalization must be preserved to avoid confusion with other abbreviations.

Science uses a standardized system of units (the Systeme International d'Unites, SI) to describe physical

quantities. This list shows the “fundamental units” ● Mass-kilogram (kg) ● Length-meter (m) ● Light intensity-candela (cd)

● Time-second (s) ● Electric current-amp (A)

● Temperature-kelvin (K) ● Amount of substance-mole (mol) (1 mole is 6.022 1023 things)

A bit more on fundamental units

The SI unit for mass is kg, but it is more common to use the g or mg.

Mass and weight are not synonymous.

Page 7: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

Chapter 0 page 3 of 8

The SI unit for length is the meter, but it is very common to use cm, mm, and nm

KNOW THIS: 1 inch = 2.54 cm (exactly)

Three different scales in common use Temp scale Freezing point, water Boiling point, water

Fahrenheit 32 °F 212 °F

Celsius 0 °C 100 °C

Kelvin 273 K 373 K

To convert between Celsius and Fahrenheit:

32CF59oo

EX. “Room temperature” is 25 °C, what is the temp in °F?

To convert from °C to K: K = °C + 273.15

EX. The flashpoint of a liquid is the lowest temperature at which the vapors will support combustion.

The flashpoint of octane (C8H18) is ~288 K. If the temperature is 12 °C (54 °F), would an arsonist be

able to use pure octane to start a fire?

Derived units

Combining fundamental units allows expression of other quantities ● Area (length2) ● Energy (mass × length2/time2) ● Acceleration (length/time2)

● Volume (length3) ● Density (mass/length3) ● Force (mass × length/time2)

● Speed (length/time) ● Frequency (1/time) ● Pressure (mass/length/time2)

Volume is defined as the amount of space an object occupies; it has no fundamental unit—but if

we had to choose the closest SI equivalence, it would be cubic meters (m3).

Page 8: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

Chapter 0 page 4 of 8

Energy is made of units involving mass, length, and time (mass × length2/time2)—what would

this be using SI units?

Other energy units: calorie, Calorie

Density is a ratio of mass to volume and is independent of the amount of material, though it is

temperature dependent

)L

g:used(also

cm

g

mL

g

volume

massDensity

3

Densities of common materials Liquid water at ~4 °C, 1.00 g/mL (KNOW THIS!!)

Solid ice at 0 °C, 0.917 g/cm3

Mercury: 13.55 g/mL

Iron: 7.87 g/cm3

NaCl: 1.54 g/cm3

Oxygen gas: 1.43·10-3 g/mL = 1.43 g/L

EX. With the high price of gold, investors need to be sure of what they are buying (or selling). If gold

has a density of 19.32 g/cm3, is a 25.0 g sample with a volume of 1.3 cm3 pure or adulterated gold?

SIGNIFICANT FIGURES

How many digits are appropriate to report in your answer? You should always report the correct number

of significant figures (or significant digits). The number of “sig figs” is equal to all of the certain digits,

plus one uncertain digit.

EX. A measurement of 2.74 cm MEANS the object is definitely between 2.7 and 2.8 cm. The 0.04 is the

best guess.

2.74 cm REALLY MEANS 2.74 ± 0.01 = the range 2.73 to 2.75 cm (3 sig figs)

EX. 313.6 g REALLY MEANS the value has a range of 313.5 g to 313.7 g (313.6 ± 0.1) (4 sig figs)

Page 9: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

Chapter 0 page 5 of 8

How many sig figs are in these numbers?

2.04

423.05

0.00630

1.2 × 10 3

1.20 × 10 3

1.200 × 10 3

1200

1200.

Mathematical operations with significant figures Addition/Subtraction: Line up the decimal, perform the operations, drop those digits that are undefined

EX. 18.43 + 1.27304 EX. 44.89 + 0.002

Note: It is possible to gain or lose sig figs with addition and subtraction operations.

EX. 85.86+ 26.41 EX. 70.6 - 67.6

Multiplication/Division: Round the answer to the number of sig figs that are found in the original

number with the fewest sig figs

EX. 5.30 × 90.51146

EX. 027.0

38.52 EX. 3025.286.31

987.77.44

Rounding

If the digit to the right of where you are rounding is < 5, truncate

If the digit to the right of where you are rounding is > 5, round up

If the digit to the right of where you are rounding is = 5, round up if it will make the final digit

even, otherwise, truncate.

EX. Round the following to the underlined digit:

1.234 =

1.236 =

1.235 =

1.245 =

1.24500000000000001 =

Page 10: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

Chapter 0 page 6 of 8

Only round at the END of your calculation Why do we follow these rules?

(1) The “rounding-with-5”-rule avoids number bias. The chance of rounding up or down is 50/50.

(2) It’s systematic. If everyone follows these rules, everyone should get the same answer—every time.

Precision is improved!

Precision -how close measurements are to each other

Accuracy -how close measurements are to the true value.

Unit Conversion

1 simple formula:

(original quantity) x (conversion factor) = (equivalent quantity with new units)

(original quantity) x (conv. factor 1) x (conv. factor 2) x (conv. factor 3)... = equiv. quant

EX. How many eggs do you have if you have 2 dozen eggs?

EX. Given the information in the table, if you have 3 A's, how many B's do you have? How many E's do

you have? 1A = 4B

6B = 5C

7C = 4.8D

2D = 4.76E

EX. Convert 19.5 m to km.

EX. Convert 55.90 g to μg.

EX. The largest wingspan of a bird on record is of a wandering albatross at 11 ft 11 inches. How many

meters is this?

Page 11: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

Chapter 0 page 7 of 8

EX. Convert 4.79 km to yards.

EX. My dog, a Pembroke Welsh corgi, sheds a LOT of hair. One estimate is that

she sheds 174.3 pounds per year. If 13,497 hairs has a mass of 5.000 g, how

many days until 9.00 106 hairs are shed?

EX. The sun consumes 5.8 108 metric tons of hydrogen atoms each second. If 1 hydrogen atom is

1.67372 10-24 grams, how many moles of hydrogen are being used in 1.000 hour?

EX. To break bone, a bullet typically needs to travel 213 feet per second. Would a bullet traveling at

120. miles per hour be fast enough?

EX. The lowest lethal concentration of ozone reported is 2.7 g/m3. If a room was measured to have a

concentration of 13.65 mg/ft3, would the concentration be high enough to kill?

Page 12: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

Chapter 0 page 8 of 8

EX. In arson investigations the heat of combustion is an important property telling how much energy is

given off when something burns. Which has a greater heat of combustion: methane (3.7 104 kJ/m3) or

gasoline (1.93 104 Btu/lb). Note that 1 Btu = 1055 J (not exact) and for gasoline, 0.70 g = 1 mL.

EX. The Glaister equation,

death since hours1.5

F)in (body temp98.4 0

, is used to estimate time of death by

measuring body temperature. What is the body temperature, in Celsius, if the body is found 435 minutes

after death?

Page 13: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

Significant Figures Worksheet

Remember the rules for sig figs and keep track of significant versus non-significant digits, but underlining the non-significant

ones. Also, DO NOT ROUND any number, until the very end of the calculation. Doing so may cause your result to be

different than the answer.

1. 4.993 + 0.743 + 1.22

2. 6.1 + 123.51 + 16.216

3. 12.43 6.7 99.220

4. 16.47 - 2.47

5. 23.71 + 11.29

6. 6.731103 + 2.114105

7. 6.73110-3 + 2.11410-5

8. 125.0 12.0

9. 9083.17

31.1241.66

10. 8.128.16

4.3214.12

11. 00.1000.10

0.10841.9

12. 00.10000.10

00.10841.9

13. m 1

nm 10

cm 100

m 1

in 1

cm 2.54

ft 1

in 12ft 6.763

9

Page 14: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

Significant Figures Worksheet Answers

1. For addition and subtraction, line up the numbers by the decimal place, perform the operation, then determine where digits

are undefined.

2. For multiplication and division, use the value with the fewest significant figures and apply that number to the product or

quotient.

3. If you have mixed operations (addition and multiplication, for instance), you must use the order of operations and keep

track of the significant digits AT EACH STEP.

4. DO NOT ROUND any number until the very end of your calculation. With a calculator, this shouldn’t be difficult since

most calculators have storage locations to keep numbers (often up to 15 digits long).

1. 4.993 + 0.743 + 1.22

4.993 (4 sig figs)

0.743 (3 s. f.)

+ 1.22_ (3 s. f.)

¯¯¯¯¯¯¯

6.956 = 6.96 (3 sig figs)

2. 6.1 + 123.51 + 16.216

6.1_ _ (2 s. f.)

123.51_ (5 s. f.)

+ 16.216 (5 s. f.)

¯¯¯¯¯¯¯

145.826 = 145.8 (4 s. f.)

3. 12.43 6.7 99.220 = 8263.14082 = 8.3 103

4. 16.47 - 2.47

16.47 (4 s.f.)

- 2.47 (3 s.f.)

¯¯¯¯¯¯¯

14.00 (4 s.f.)

5. 23.71 + 11.29

23.71 (4 s. f.)

+ 11.29 (4 s. f.)

¯¯¯¯¯¯¯

35.00 (4 s.f.)

6. 6.731103 + 2.114105

Line up values by decimal place, to the same power of 10!

6731 (4 s. f.)

+ 211400 (4 s. f.)

¯¯¯¯¯¯

218131 = 2.181 105 (4 s. f.)

7. 6.73110-3 + 2.11410-5

0.006731_ _ (4 s. f.)

+ 0.00002114 (4 s. f.)

¯¯¯¯¯¯¯¯¯¯¯

0.00675214 = 0.006752 or 6.752 10-3 (4 s. f.)

8. 125.0 12.0 = 1500 = 1.50103 (3 s. f.)

(4 s. f.) (3 s. f.)

9. 9083.17

31.1241.66 =

f. s. 6

f. s. 4

9083.17

10.54 = 3.020945595

= 3.021 (4 s. f.)

10. 8.128.16

4.3214.12

=

f. s. 2

f. s. 3

0.4

336.339 = 98.334

= 98 (2 s. f.)

11. 00.1000.10

0.10841.9

=

f.) s. (5 00.100(3s.f.) 0.10

(1s.f.) 591.0

= f.) s. (5 00.100(1s.f.) 5901.0

= -1.59 (1 s. f.) = -2 (1 s. f.)

12. 00.10000.10

00.10841.9

=

f.) s. (5 00.100(4s.f.) 00.10

(2s.f.) 915.0

= f.) s. (5 00.100(2s.f.) 9015.0

= -1.59 (2 s. f.) = -1.6 (2 s. f.)

13. m 1

nm 10

cm 100

m 1

in 1

cm 2.54

ft 1

in 12ft 6.763

9

= 2061362400 = 2.061 109 (4 s. f.)

Note in #13, each conversion factor has an infinite

number of significant figures, the result is limited by the

first value (6.763 ft).

Page 15: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

CHEM 111 Unit simplification worksheet

As you progress though chemistry, unit conversions and formulas that involve units will become a very important aspect to

understanding the material. In the worksheet below, determine the unit(s) that result from each calculation. Numbers have

been omitted for clarity, just focus on the units. Simplify derived units to the fundamental unit counterparts, but don’t include

conversions unless they are given in the problem.

(a) kg×g

kg×

cm

g

(b) (J×s)(m

s⁄ )

nm×

nm

m

(c) (J×s)

kg×𝑚𝑠⁄ note that 1 J = 1 kg•m2/s2

(d) 1

(1

g)

(e) g

(1

cm)

×cm

(f) (J×s)×m/s

kJmol⁄

×1

mol×

kJ

J

(g) (J×s)

mg×kmh⁄

(h) (J×s)

mg×kmhr

⁄× mg

g× g

kg× km

m× hr

s

Answers:

(a) cm

(b) J (i.e., kgm2/s

2)

(c) m

(d) g

(e) gcm2

(f) m

(g) kg×𝑚2/s

mg×𝑘𝑚ℎ⁄

=kg×𝑚2×h

s×mg×km (these are nonsensical units, but the point is to see what

units cancel and which don’t)

(h) m×hr2/s

2

Page 16: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

Chapter 1 page 1 of 9

CHEM 111-Chapter 1

The Structure and Stability of Atoms

Chapter 1 Problems: 1-57, 59-107, 110-113

What is the nature of matter?

Empedocles (492-432 BCE) is credited with categorizing matter as mixtures of four elements: earth, air,

fire, and water. (Plato (427-347 BCE) later added a fifth element: the ether.)

First "atomic" theory proposed by Democritus (460-370 BCE)

Democritus’ ideas were not entirely correct

atoms ARE breakable

atoms don't come in an infinite number of shapes

atoms don't come in an infinite number of types

Element: a fundamental substance that can't be chemically changed or broken down into anything

simpler

Good News: There are only 118! (currently)

Other Good News: We’ll focus primarily, but not exclusively, on ~90!!

Elemental symbols: 1 or 2 letter abbreviations of the full name. First letter is ALWAYS capitalized,

second letter is NEVER capitalized. Note elements 114 and 116...

Most elemental symbols are derived from the English name of the element, but not all...

Page 17: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

Chapter 1 page 2 of 9

In 1869 Russian chemist Dmitri Mendeleev derived an ingenious way to arrange the elements according

to how they react. Elements in a column had similar reactivities. This was called the “periodic law” and

was the precursor to our modern periodic table.

Elements can be divided into different sections based on location or properties

1. Metals (most elements)

Properties: shiny, silvery in color (exceptions?), solid at room temperature (exceptions?), malleable

(able to be hammered into thin sheets), sectile (able to be cut into thin sheets), ductile (able to be drawn

into wires), good conductor of heat, and good conductor of electricity. (Hardness is NOT a property of

metals.)

EX. Aluminum (Al): used in airplanes, cola cans, cooking foil

Iron (Fe): used for structural materials (cars, buildings, desks)

Gold (Au): used in dentistry, jewelry, computer contacts

2. Non-metals (17 elements)

Properties: May be solid, liquid, or a gas at room temperature (depends on the element), variety of

colors, if solid will be brittle (thus, not malleable, sectile, or ductile), very poor conductors of heat, and

very poor conductors of electricity.

EX. Nitrogen (N): ~78% of air

Oxygen (O): ~21% of air

Argon (Ar): ~1% of air

Chlorine (Cl): yellow gas, used to disinfect water (drinking and pools)

Bromine (Br): red liquid, used to disinfect hot tub water

Iodine (I): purple solid, used as a topical disinfectant

3. Metalloids (aka semimetals) (7 elements-B, Si, Ge, As, Sb, Te, At)

Properties: Solid at room temperature, brittle, conduct heat and electricity better than nonmetals, but

not as well as metals.

Silicon (Si): finds many uses in computer circuitry and solar cells

Boron (B): used in control rods for nuclear reactors

Rows versus columns.

Elements in a group react in similar ways.

Some Special Groups

1-alkali metals-Li, Na, K, Rb, Cs, Fr

2-alkaline earth metals-Be, Mg, Ca, Sr, Ba, Ra

15-pnictogens (nitrogen group)-N, P, As, Sb, Bi

16-chalcogens (oxygen group)-O, S, Se, Te, Po

17-halogens-F, Cl, Br, I, (At)

18-noble gases-He, Ne, Ar, Kr, Xe, Rn

11 or 1B-coinage metals-Cu, Ag, Au

Four Classifications of properties

Physical property: Characteristics that can be determined without changing the chemical makeup of the

sample

Chemical property: Characteristics that DO change the sample (the sample undergoes a chemical

reaction).

See table 1.3, pg 32

Page 18: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

Chapter 1 page 3 of 9

Extensive property: A property that DOES depend on the amount of sample

Intensive property: A property that is independent of the amount of sample.

Examples of extensive properties: mass, volume, length/width, etc.

Examples of intensive properties: temperature (boiling point, melting point, too), hardness, conductivity

(heat and electrical), color, etc.

Some Chemical History Next big step in atomic theory: Robert Boyle (1627-1691)

-clearly defined the term element and determined that when different elements combined a new

substance called a compound was formed.

Next big step: Antoine Lavoisier (1743-1794)

Law of Mass Conservation: Matter is neither created nor destroyed in chemical reactions

Major chemical principle #2: Joseph Proust (1754-1826)

Law of definite proportions: Different samples of a pure chemical substance always contain the same

proportion of elements by mass.

John Dalton (1766-1844) proposed two important concepts:

Law of Multiple Proportions: Elements can combine in different ways to form different chemical

compounds, but their mass ratios must be simple whole numbered multiples

Dalton’s Theory of Matter (1) Elements are made of tiny particles called atoms

(2) Each element is characterized by the mass of its atoms. Atoms of the same element have the same

mass, but atoms of different elements have different masses.

(3) Chemical combinations of elements to make different substances occur when atoms join together in

small, whole number ratios.

(4) Chemical reactions only rearrange the way atoms are combined; the atoms themselves are not

destroyed.

Page 19: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

Chapter 1 page 4 of 9

Atomic structure Radioactivity proved atoms were made of smaller components

Experiments with beta-rays (beta particles, -particles)

J. J. Thomson (1856-1940) and others used cathode ray tubes to study a beam of particles that flowed

toward a positive wire. These were called electrons. By careful manipulation of magnetic and electric

fields, Thomson calculated the charge-to-mass ratio of the electron (Figure 2.3):

-e/m = -1.758820 108 C/g

R. A. Millikan (1868-1953) designed the “oil drop experiment” to measure the electron's charge (Figure

2.4). If Millikan’s result was -e=-1.602176 10-19 C, then what is the mass of an electron?

Early atomic models

Democritus

Dalton

Plum Pudding

In 1911, Ernest Rutherford blew all of these models away with one "simple" experiment.

Page 20: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

Chapter 1 page 5 of 9

What IS the nucleus?

Protons

Symbol: p or p+

has a +1 charge

mass of 1.672622 10-24 g (this is ~1836 times the mass of an electron)

Neutrons (theorized by Rutherford, but not discovered until 1933)

Symbol: n

no charge

mass of 1.674927 10-24 g

In a neutral atom, the number of protons = the number of electrons

ATOMIC NUMBER (Z): the number of protons in the nucleus of an atom

This is the defining characteristic of an element!!!

Atoms of the same element CAN have different numbers of neutrons

Page 21: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

Chapter 1 page 6 of 9

For instance, there are three types of hydrogen atoms

“protium” = 1 proton, 0 neutrons

“deuterium” = 1 proton, 1 neutron

“tritium” = 1 proton, 2 neutrons (unstable and radioactive)

ALL contain 1 proton, but different numbers of neutrons. What effect does this have on the mass of

each kind of hydrogen?

ISOTOPES: atoms with identical atomic numbers, but different numbers of neutrons

MASS NUMBER (A): Total number of n and p+ in an atom

A = Z + n

EX. How many protons, neutrons, and electrons are in the following?

K3919

3Au199

79 124Sn4-

p+ = p+ = p+ =

n = n = n =

e- = e- = e- =

Different elements have different masses AND even atoms of the SAME element can have different

masses if there are multiple isotopes

Problem: Dealing with the mass (in g, kg, mg, ng, etc.) of individual atoms is inconvenient.

Solution: Use the "amu"-the atomic mass unit

1 amu = 1/12 of 12C, 1 amu = 1.66054 10-24 g (not exact)

so...12C has a mass of 12.000000 amu

Note that atoms have just one mass listed on the periodic table—the so-called atomic mass—even if

there are mutliple isotopes.

ATOMIC MASS (ATOMIC WEIGHT): the weighted average of all the isotopic masses of an

element's naturally occurring isotopes

EX. Chlorine consists of two isotopes, 35Cl (mass = 34.9688527 amu, % abund = 75.77%) and 37Cl (mass = 36.9659026 amu, % abund = 24.23%). What is the atomic mass?

Note the close relationship between an atom’s mass in amu and its mass number...

Note: Some atoms only have one isotope, thus the atomic mass IS the mass of those particular atoms.

Page 22: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

Chapter 1 page 7 of 9

Be, 9.01218 amu

F, 18.99840 amu

Na, 22.98977 amu

These atomic masses give you a way to convert between the number of atoms and the mass.

EX. What mass (in amu) is 5000. titanium atoms? What is this mass in grams?

Better yet, because of a wise choice in how the amu is defined, there is a link to the value of the mole.

EX. How many atoms are in 12.0107 g of C?

So 1 carbon atom = 12.0107 amu, but 6.022 1023 (an Avogadro’s number, i.e., 1 mole) of carbon = 12.0107 g

The atomic mass, expressed in units of grams instead of amu, is called the molar mass.

EX. 1 Fe atom = ____________ amu; 1 mole of Fe = _______________ grams

EX. 1 Mg atom = ____________ amu; 6.022 1023 Mg atoms = _______________ grams

EX. How many moles of Hg are present in a medical thermometer which contains 2.5 g of Hg?

EX. If a rebar has 9.941 g of Fe per centimeter of length, how many Fe atoms are there in 2.50 feet of

rebar?

Nuclear Chemistry

Page 23: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

Chapter 1 page 8 of 9

Alchemy was the magical belief that elements could become a totally new element (i.e., transmutation).

Once chemical principles were discovered, this old way of thinking was discarded...until radioactivity

was discovered in the 1890s.

Like chemical reactions, nuclear reactions are written with a specific format:

Reactants Products

and the reactions must be balanced—with respect to Z and A. Reactions are balanced by ADDING the

correct species to either the reactant or product side—NEVER use a subtraction in a reaction!!

ALSO: DO NOT use an equals sign (=) between reactants and products, use an arrow ()

Nuclear reactions don’t concern themselves with charges on ions—focus on what’s happening to the

nucleus.

EX. The spontaneous break up of 235U can lead to multiple products

U23592 Tc105

43 + Ag12647 + He4

2

Types of Radioactive Decay

Gamma (γ) radiation-results from emission of high energy light from the nucleus—often left out of

nuclear reactions because it doesn’t change the number of protons or neutrons

EX. The cobalt-58 nucleus can exist (temporarily) in an unstable state, which gives off γ radiation to

become more stable.

*58

27Co Co58

27 + γ

In almost all nuclear reactions, gamma radiation results, even if other particles are emitted.

Alpha (α) radiation-results from emission of a helium nucleus ( 242 He , just written as He4

2 or 4

2α)

EX. Write the reaction for the alpha emission of americium-241, an element found in smoke alarms.

Beta (β-) radiation-results from emission of an electron from the nucleus ( eor β 01-

01-

)

How is this electron created? Note the Law of Charge Conservation: The net charge of an isolated

system remains constant. Charge can be created and destroyed, but only in positive-negative pairs.

EX. Technetium-99 is used as a radioactive tracer in medicine. What products result when it undergoes

β-decay?

What does this say about the stability of neutrons?

Page 24: Table of Contents (italicized entries indicate worksheets ...faculty.uscupstate.edu/cbender/Courses/C111/CHEM... · Table of Contents (italicized entries indicate worksheets and extra

Chapter 1 page 9 of 9

Positron (β+) emission-results from the emission of an antimatter electron (positron) from the nucleus ( β01

)

How is the positron created?

EX. “PET scans” are used in medicine to locate tumors and monitor certain types of brain activity.

Sugar molecules containing fluorine-18, a known positron emitter, are taken by the patient—what is the

β01

emission reaction?

What ultimately happens to the positron?

Electron capture (E. C.)-process whereby an electron is sucked into the nucleus and converts a proton

into a neutron

EX. While chromium has stable isotopes with mass numbers of 50, 52, 53, and 54, chromium-51 is

unstable and undergoes electron capture—what is the reaction?

Other nuclear reactions are also possible, but not discussed in the book. Atoms may emit protons,

neutrons, a proton/neutron pair (deuteron), and other subatomic particles, but these are rare.

Nuclei can also be “encouraged” to react by bombardment of nuclei with neutrons, protons, or even

larger atoms.

The heavy atoms recently created had large nuclei that were smashed together at enormous speeds. This

is the reaction that created the first copernecium atoms.

Pb20882 + Zn70

30 Cn278112