review class...

1

Chemistry 51

Spring 2018

Ticket 11540

5:15 PM to 8:55 PM

Tuesday AND Thursdays

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Review class syllabus

44

Lab CMS-201Tuesday & Thursday7:30 PM to 8:55 PM

Dr. OrzechowskaLab CMS-203

Tuesday & Thursday7:30 PM to 8:55 PM

Mallory

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5

2

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OPTION TEXT IMAGE TEXT Reasons for this Option Reasons against this Option

A

General, Organic and Biological Chemistry, Timberlake, 1st Ed. (ISBN 9781269061001)

• Contains access to the online homework

• This text is custom published for LAMC and only includes chapters used in the course.

• Bundled with online homework access ($66.00 value)

• $148.38

B

General, Organic and Biological Chemistry, Timberlake, 1st Ed. (ISBN 9781269061001)

• Available on reserve in the LAMC library

• This text is custom published for LAMC and only includes chapters used in the course.

• $0.00 for textbook

• $66.00 for online homework access

• Others may be using the book at the time you need it.

C

General, Organic and Biological Chemistry, Timberlake, 4th Ed. (ISBN 9780321750129)

• This is the original textbook from which the custom text was prepared.

• It is available for purchase from online retailers.

• Rental from $20 - $100 for the semester

• Used from $?? - $125

• $66.00 for online homework access

• Shipping time • New from $150 - $500

D

An Introduction to General, Organic,and Biological Chemistry 12th Ed. Timberlake (ISBN 9780321908445)

• None • Cost• I found PowerPoint slides for

the other editions. So this is not a good choice.

Chemistry 51SELECTING A TEXTBOOK•Although I provide complete set of lecture notes for the course on my website, the textbook for this course provides many benefits and resources that could help you succeed in the course. •In order to provide you with options for purchase and use of the textbook, several choices are available and discussed below.•Please make informed decisions when purchasing your text and weigh the cost and benefits of each option before you make your decision. •Please note that I will not be using the online homework option and using the assigned homework exercises as shown on my website.

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88 99

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1010

101111

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1212 1313

Confirmationof who iscurrently enrolled

Who is here… Who wants to add..

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Smarter than you Takes good notesPrepares for class

Follows directionsWashes dishes

Always shows up

Wants to forma study group

Dedicated

Trustworthy

CHEMISTRY AND CHEMICALS

Chapter 1 §1.1

5:15 PM – 7:20 PM

17

Chemistry

Chemistry is the study of matter and its composition, structure, properties, and reactions.

Mass (like weight) and Volume18

Chemistry is Everywhere

Chemistry happens allaround you, for example,when you:

breathe cook food grow plants digest food, and even when you drop an antacid tablet in a glass of water.

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19

Field of Chemistry

The field of chemistry is divided into branches. General Chemistry Organic Chemistry Biochemistry Analytical Chemistry Inorganic Chemistry Physical Chemistry and MORE!

Biochemists analyze samples in a laboratory.

20

Alchemists: Early Chemists

Alchemists learned to extract

metal from ores, designed some of

the first laboratory equipment, and

developed early laboratory procedures.

Paracelsus believed that chemicals and minerals could be used as medicines.

Paracelsus, born Philippus Aureolus Theophrastus Bombastus von Hohenheim, was a Swiss German philosopher, physician, botanist, astrologer, and general occultist. He is credited as the founder of toxicology. Born: 1493, Einsiedeln, SwitzerlandDied: September 24, 1541, Salzburg, Austria Education: University of Vienna, University of Ferrara, University of BaselMain interests: Alchemy, Astrology

21

Chemicals

Chemicals are substances that always have the same

composition and properties, in everything you see, and also called substances and describe a specific

type of material.

2222

What is a chemical?

Hydrochloric Acid Sodium ChlorideWater Air People Table Salt Oxygen Carbon Dioxide…

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2323

Common Products Contain ChemicalsSubstances you use everydaycontain chemicals, including shampoo, soap, and toothpaste.

2424

Chemicals Commonly Used in Toothpaste

25

Learning Check

List 5 chemicals you might find in your kitchen.

26

Solutions

Five chemicals you might find in your kitchen include:

1. Calcium carbonate is found in kitchen countertops.2. Sodium bicarbonate is found in baking soda.3. Sugar 4. Salt5. Acetic acid is found in vinegar.

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2727

A STUDY PLAN FOR LEARNING CHEMISTRY

Chapter 1 §1.2

5:15 PM – 7:20 PM28

Text Features to Help You Study Chemistry This text contains study features to complementyour learning style, such as a periodic table on the inside front cover tables with useful information on inside back

cover Looking Ahead at the start of each chapter Learning Goals at the beginning of each section a Glossary and Index at end of text

29

Chapter Features

Before reading, review topics in Looking Ahead. Review Learning Goals at the beginning of each

section. Solve Concept Checks to help you understand

the key ideas in each chapter. After reading, work through Sample Problems

and try the associated Study Checks. Work the sets of Questions and Problems at the

end of each section.

30

Chapter Links to Real-Life

Throughout the chapters, there are features that helpyou connect the concepts to real-life situationsincluding Chemistry Link to Health, Chemistry Link to the Environment, Chemistry Link to Industry, and Chemistry Link to History.

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31

Chapter Figures

Many figures and diagrams contain macro-to-micro illustrations that depict the atomic level of organization of ordinary

objects, illustrate concepts described in the text, and allow you to see the world in a microscopic way.

32

End of Chapter Study Aids

At the end of each chapter, you will find study aidssuch as Concept Maps that show connections between

important concepts, Chapter Reviews that provide a summary, Key Terms that include definitions, Understanding the Concepts, a set of questions

that help to visualize concepts, and Additional Questions and Problems and

Challenge Problems to test your understanding.

3333

Combining Ideas

At the end of some chapters, problem sets calledCombining Ideas will test your ability to solveproblems that combine concepts from previouschapters.

3434

Active Learning

Use Active Learning methods to help you learn chemistry. Practice problem solving. Note questions you have about the reading to discuss

with your professor or laboratory instructor. Read all assigned materials before you attend lectures. Attend the Professor's office hours for help.

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35

Form a Study Plan

36

Learning Check

Which of the following activities would you NOTinclude in your study plan for learning chemistrysuccessfully?

A. reading the assigned materials before lectureB. making notes in your text when you have

questionsC. forming a study groupD. waiting until the night before the exam to

study

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Solution

Which of the following activities would you NOTinclude in your study plan for learning chemistrysuccessfully?

D. waiting until the night before the exam tostudy

Science Success Center

A great place to get helpRoom: CMS

Hours: 11:00AM – 7:00 PM

Days: Monday through Thursday

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3939

UNITS OF MEASUREMENT

Chapter 1 §1.3

5:15 PM – 7:20 PM40

Measurements

walking 2.1 km to campus, carrying a backpack with a mass of 12 kg, and observing when the outside temperature has reached 22

oC.

We use measurements in everyday life, such as

4141

The Metric System (SI)

The metric system and SI (Système International)are used

for length, volume, mass, temperature, and time, in most of the world (except for the US), and everywhere by scientists.

4242

Units in the Metric System

In the metric and SI systems, one unit is used for eachtype of measurement.

Measurement Metric SI EnglishLength meter (m) meter (m) inchVolume liter (L) cubic meter (m3) gallonMass gram (g) kilogram (kg) slugTemperature Celsius (C) Kelvin (K) FahrenheitTime second (s) second (s)

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43

Length MeasurementLength is measured using a meter stick. uses the unit meter

(m) in both the metric and SI systems. uses centimeters

(cm) for smaller units of length.

44

Inches, Centimeters, and Meters

Useful relationships between units of length

2.54 cm = 1 inch (exact)1m = 100 cm (exact)1m = 39.4 in1m = 1.09 yard

Length in the English System12 inches = 1 foot (exact)3 feet = 1 yard (exact)220 yards = 1 furlong (exact)8 furlongs = 1 mile (exact)

45

Volume Measurement

Volume is the space occupied by a substance. uses the unit liter (L) in the metric system.

1L = 1.06 qt uses the unit cubic meter (m3) in the SI

system. is measured using a graduated cylinder in

units of milliliters (mL). 46

Quarts, Liters, and Milliliters

Useful relationships between units of volume

1L = 1000 mL (exact)1L = 1.06 quarts94 ml = 1 quart1000 L = 1 m3

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4747

Volume in general

Unit Divisions

1 cubic inch (cu in) or (in3)

1 cubic foot (cu ft) or (ft3) 1728 cu in1 cubic yard (cu yd) or (yd3) 27 cu ft1 acre-foot (acre ft) 43560 cu ft 1613.333 cu yd

Liquid volumeUnit Divisions

1 minim (min) ~1 drop or 0.95 grain of water1 US fluid dram (fl dr) 60 min1 teaspoon (tsp) 80 min1 tablespoon (Tbsp) 3 tsp or 4 fl dr1 US fluid ounce (fl oz) 2 Tbsp or 1.0408 oz av of water1 US shot (jig) 1.5 fl oz or 3 Tbsp1 US gill (gi) 22⁄3 jig or 4 fl oz1 US cup (cp) 2 gi or 8 fl oz1 (liquid) US pint (pt) 2 cp or 16.65 oz av of water1 (liquid) US quart (qt) 2 pt1 (liquid) US gallon (gal) 4 qt or 231 cu in1 (liquid) barrel (bbl) 31.5 gal or 1⁄2 hogshead1 oil barrel (bbl) 11⁄3 (liquid) barrel or 42 gal or 2⁄3 hogshead1 hogshead 1.5 oil barrels or 63 gal or 8.421875 cu ft or 524.7 lb of water

Dry volume

Unit Divisions

1 (dry) pint (pt) 33.60 cu in

1 (dry) quart (qt) 2 pt1 (dry) gallon (gal) 4 qt or 268.8025 cu in1 peck (pk) 2 gal

1 bushel (bu) 4 pk or 1.244 cu ft

1 (dry) barrel (bbl) 7056 cu in or 3.281 bu NO!

4848

Mass Measurement

The mass of an object is a measure of the quantity

of material it contains. measured in grams (g) for

small masses. is measured in kilograms

(kg) in the SI system.

The standard kilogram forthe United States is stored at the National Institute of Standards and Technology.

4949

Pounds, Grams, and Kilograms

Useful relationships between units of mass

1 Kg = 1000 g (exact)1 kg = 2.20 pounds4.54 g = 1 pound

5050

Pounds, Grams and Kilograms

In a chemistry laboratory,an analytical balance isused to measure the massof a substance in grams.

On an electronic balance, a nickel has a mass of 5.01 grams.

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51

Temperature Measurement

measured on the Celsius(C) scale in the metric system,

measured on the Kelvin (K)scale in the SI system, and

18°C or 64°F on this thermometer.

Temperature indicates how hot or cold a substance is, and is

52

Time Measurement

Time measurement uses the unit second (s)

in both the metric and SI systems.

uses an atomic clock to measure a second.

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Days, Hours, Minutes, Seconds

Useful relationships between units of time

1 day = 24 hours (exact)1 hour = 60 minutes (exact)1 minute = 60 seconds (exact)365.25 days = 1 year

5454

For each of the following, indicate whether the unit describes length, mass, or volume. ________ A. A 10.0 lb bag of tomatoes is 4.5 kg.

________ B. A person is 2.0 m tall.

________ C. A medication contains 0.50 g of aspirin.

________ D. A bottle contains 1.5 L of water.

Learning Check

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5555

For each of the following, indicate whether the unit describes length, mass, or volume.

mass A. 10 lb A bag of tomatoes is 4.5 kg.

length B. A person is 2.0 m tall.

mass C. A medication contains 0.50 g of aspirin.

volume D. A bottle contains 1.5 L of water.

Solution

5656

Learning Check

Identify the measurement that has an SI unit. 1. John’s height is _____.

A. 1.5 yd B. 6 ft C. 2.1 m

2. The race was won in _____. A. 19.6 s B. 14.2 min C. 3.5 h

3. The mass of a lemon is _____.A. 12 oz B. 0.145 kg C. 0.62 lb

4. The temperature is _____.A. 85 °C B. 255 K C. 45 °F

5757

Solution

Identify the measurement that has an SI unit. 1. John’s height is _____.

C. 2.1 m

2. The race was won in _____.A. 19.6 s

3. The mass of a lemon is _____. B. 0.145 kg

4. The temperature is _____.B. 255 K

5858

SCIENTIFIC NOTATION

Chapter 1 §1.4

5:15 PM – 7:20 PM

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Scientific NotationScientific Notation is used to write very large or very small numbers. is used to give the width of a human hair (0.000 008 m)

as 8 x 10-6 m.

for a large number such as 100 000 hairs is written as 1 x 105 hairs. 6060

Writing Numbers in Scientific Notation A number in scientific notation contains a coefficient

between 1 and 10 and a power of 10 and a unit.

For numbers larger than 1, the power of 10 is positive.

6161

Writing Numbers in Scientific Notation

For numbers smaller than 1, the power of 10 is negative.

6262

Some Powers of Ten

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6363

Scientific Notation and Calculators You can enter a number in scientific notation on

many calculators using the EE or EXP key.

Use the (+/−) key to change the value of the exponent from positive to negative.

6464

Scientific Notation and CalculatorsWhen a calculator display appears in scientific notation,it is shown as a number between 1 and 10 followed by aspace and the power of 10.

6565

Scientific Notation and Calculators

To write this number in correct scientific notation, writethe coefficient and use the power of 10 as an exponent.

6666

Converting Scientific Notation to a Standard NumberWhen a number in scientific notation has a positivepower of 10, move the decimal point to the right for the same

number of places as the power of 10 and add placeholder zeros to give the additional decimal

places needed.

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6767

Converting Scientific Notation to a Standard NumberWhen a number in scientific notation has a negativepower of 10, move the decimal point to the left for the same

number of places as the power of 10 and add placeholder zeros in front of the coefficient as

needed.

6868

Learning Check

Select the correct scientific notation for each.

1. 0.000 000 08 mA. 8 x 108 m B. 8 x 10−8 m C. 0.8 x 10−7 m

2. 72 000 LA. 7.2 x 104 L B. 72 x 103 L C. 7.2 x 10−4 L

6969

Solution

Select the correct scientific notation for each.

1. 0.000 000 08 mB. 8 x 10−8 m

2. 72 000 LA. 7.2 x 104 L

7070

Learning Check

Write each as a standard number.

1. 2.0 x 10−2 sA. 200 s B. 0.0020 s C. 0.020 s

2. 1.8 x 105 g A. 180 000 g B. 0.000 018 g C. 18 000 g

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7171

Solution

Write each as a standard number.

1. 2.0 x 10−2 sC. 0.020 s

2. 1.8 x 105 gA. 180 000 g

7272

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7373

MEASURED NUMBERS AND SIGNIFICANT FIGURES

Chapter 1 §1.5

5:15 PM – 7:20 PM74

Representing Measured Numbers

Measured numbers are numbers obtained by usingmeasuring devices, such as

a scale or analytical balance, a graduated cylinder, a clock or stopwatch, or a ruler

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Representing Measured Numbers

On a metric ruler with lines marking divisions of 0.1cm, write the length to 0.1 cm and estimate the valueof the final number to 0.01 cm by visual inspection.

7676

Significant Digit Rules1. All non-zero digits are significant

i.e. 123456789 (9)

2. All leading zeros are NOT significant 00.0002 (1)

3. All trailing zeros to the right of the decimal point are significant. i.e. 1.00000 (6)

4. All sandwiched zeros are significant i.e. 1000.001 (7)

5. All trailing zeros to the left of the decimal point are NON significant i.e. 12300 (3)

7777

Significant Digits – More Stuff

For measured numbers, you are never sure of the last digit. (It is significant, but you are not sure of the number.)

Significant trailing zeros to the left of the decimal point can be shown as significant by placing a bar above the zero. 0

Exact Numbers... Have infinite significant digits. Like people in this class.

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Rules for Significant FiguresIn a measured number, the significant figures (SFs)are all digits including the estimated number. A number is a significant figure if it is

a nonzero number. (234 g, 3 SF) a zero between nonzero numbers.

(50071 g, 5 SF) a zero at the end of a decimal number.

(50.00 m, 4 SF) the coefficient of a number is written in

scientific notation. (2.0 x 103 m, 2 SF)

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Scientific Notation and Significant ZerosWhen one or more zeros in a large number aresignificant, they are shown more clearly by writing thenumber in scientific notation.

5,000. kg 5.000 x 103 kg

If zeros are not significant, we use only the nonzeronumbers in the coefficient.

5,000 kg 5 x 103 kg

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Exact Numbers

Exact numbers are those numbers obtained by counting items. those numbers in a definition comparing two units

in the same measuring system. not measured and do not affect the number of

significant figures in a calculated answer.

1.81 Round off or add zeros to the following calculated answers to give a final answer with three significant figures:

a. 0.00001258 Lb. 3.528 x 102 kgc. 125111 md. 58.703 g

a. 0.0000126 Lb. 3.53 * 102 kgc. 125000 md. 58.7 g

1.82 Round off or add zeros to the following calculated answers to give a final answer with two significant figures:

a. 0.004 mLb. 34 677 gc. 4.393 cmd. 1.74 x 103 ms

a. 0.0040 mLb. 35000 gc. 4.4 cmd. 1.7 * 103 ms

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8383

SIGNIFICANT FIGURES IN CALCULATIONS

Chapter 1 §1.6

5:15 PM – 7:20 PM84

Calculations with Measured NumbersThe number of significantfigures in measurednumbers are used to limitthe number of significant figures in the final answer.

Calculators do not providethe appropriate number ofsignificant figures.

8585

Rounding Rules

If the value is less than five, then round down If the value is greater than five, then round

up If the value is equal to five…

Round to make the number even. i.e. 1.25 -> 1.2 & 1.35 -> 1.4

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Rounding Off

To represent the appropriate number of significantfigures, we use "rules for rounding."

1. If the first digit to be dropped is 4 or less, then it, and all following digits are simply dropped from the number.

2. If the first digit to be dropped is greater than 5, then the last retained digit of the number is increased by 1.

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8787

When multiplying or dividing Use the same number of significant figures (SF) as

the measurement with the fewest number of significant figures

Use the rounding rules to obtain the correct number of significant figures.

Multiplication and Division

8888

Do some random examples on the board

Learning Check

8989

Sometimes we add one or more significant zeros tothe calculator display in order to obtain the correctnumber of significant figures needed.

Example:Suppose the calculator display is 4, and you need 3 significant figures.

4 becomes 4.001 SF 3 SF

Adding Significant Zeros

9090

When adding or subtracting, use the same number of decimal places as the

measurement with the fewest decimal places and the rounding rules to adjust the number of digits in

the answer. one decimal placetwo decimal placescalculated answerfinal answer (with one

decimal place)

Addition and Subtraction

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Do some examples on the board

Learning Check

9292

PREFIXES AND EQUALITIES

Chapter 1 §1.7

5:15 PM – 7:20 PM

9393

Prefixes

A prefix in front of a unit increases or decreases the size of that

unit. makes units larger or smaller than the initial unit by one

or more factors of 10. indicates a numerical value.

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Metric and SI Prefixes

Prefixes that increase the size of the unit:

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Metric and SI Prefixes

Prefixes that decrease the size of the unit:

96

Daily Values for Selected Nutrients

9797

Indicate the unit that matches the description.

1. a mass that is 1000 times greater than 1 gramA. kilogram B. milligram C. megagram

2. a length that is 1/100 of 1 meterA. decimeter B. centimeter C. millimeter

3. a unit of time that is 1/1000 of a secondA. nanosecond B. microsecond C. millisecond

Learning Check

9898

Indicate the unit that matches the description.

1. a mass that is 1000 times greater than 1 gramA. kilogram

2. a length that is 1/100 of 1 meterB. centimeter

3. a unit of time that is 1/1000 of a secondC. millisecond

Solution

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9999

Select the unit you would use to measure

1. your height. A. millimeters B. meters C. kilometers

2. your mass. A. milligrams B. grams C. kilograms

3. the distance between two cities. A. millimeters B. meters C. kilometers

4. the width of an artery.A. millimeters B. meters C. kilometers

Learning Check

100100

Select the unit you would use to measure

1. your height. B. meters

2. your mass. C. kilograms

3. the distance between two cities. C. kilometers

4. the width of an artery.A. millimeters

Solution

101101

An equality states the same measurement in two different units. can be written using the relationships between two

metric units.

Example: 1 meter is the same as 100 cm and 1000 mm.

Metric Equalities

102102

Measuring Length

The metric length of 1 meter is the same length as 10 dm, 100 cm,and 1000 mm.Q How many millimeters (mm) are in 1 centimeter (cm)?

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103

Measuring Volume

104

Measuring Mass

Several equalities can be written for mass in the metric (SI) system.

105105

Indicate the unit that completes each of the followingequalities.

1. 1000 m = A. 1 mm B. 1 km C. 1 dm

2. 0.001 g = A. 1 mg B. 1 kg C. 1 dg

3. 0.1 s = A. 1 ms B. 1 cs C. 1 ds

4. 0.01 m = A. 1 mm B. 1 cm C. 1 dm

Learning Check

106106

Indicate the unit that completes each of the followingequalities.

1. 1000 m = B. 1 km

2. 0.001 g = A. 1 mg

3. 0.1 s = C. 1 ds

4. 0.01 m = B. 1 cm

Solution

27

107107

Complete each of the following equalities.

1. 1 kg = A. 10 g B. 100 g C. 1000 g

2. 1 mm = A. 0.001 m B. 0.01 m C. 0.1 m

Learning Check

108108

Complete each of the following equalities.

1. 1 kg = C. 1000 g

2. 1 mm = A. 0.001 m

Solution

109109

For the test…

109110110

Saftey Contract due in lab Code of integrity due in lecture

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111111 115115

HOMEWORK…

115

• Don’t forget to do your homework.

• We will go over it tonight.

• You do not need to turn it in. I will be able to tell when I grade your tests.

• BUT… since the syllabus does not take the homework into account, would you like to have it count as extra credit points???

116116

WRITING CONVERSION FACTORS

Chapter 1 §1.8

5:15 PM – 7:20 PM117117

Why Conversion is Easy…

X

1

= 1

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118118

More with Conversions

1

119119

More with Conversions

1

120120

Equalities use two different units to describe the same measured

amount. are written for relationships between units of the metric

system; between U.S. units or between metric and U.S. units. Examples:

Equalities

121121

Equalities are written as a fraction. used as conversion factors. can be represented with one equality in the numerator

and the second equality in the denominator.Examples:

Equalities and Conversion Factors

30

122122

Common Equalities

123123

Exact and Measured Numbers in EqualitiesEqualities between units of

the same system are definitions with numbers that are exact.

different systems (metric and U.S.) are measurements with numbers that have significant figures.

The equality of 2.54 cm = 1 in. is an exception and considered to be exact.

124124

Metric Conversion Factors

We can write equalities as conversion factors.

125125

Metric–US conversion factors are written as a ratio witha numerator and denominator.Example:

Metric-US Conversion Factors

31

126

Equalities on Food Labels

The contents of packaged foods in the U.S. are listed in both metric and U.S. units. indicate the same amount of a substance in two

different units.

127127

Write equalities and conversion factors for each pair of units.

1. liters and mL

2. hours and minutes

3. meters and kilometers

Learning Check

128128

Write equalities and conversion factors for each pair of units.

Solution

129129

A conversion factor may be obtained from information in a word problem. is written for that problem only.

Example 1: The motorcycle was traveling at a speed of85 km/h.

Example 2: One tablet contains 500 mg vitamin C.

Conversion Factors in a Problem

32

130130

A percent factor uses a ratio of the parts to the whole in a fraction.

uses the same units for the parts and whole. uses the value 100 for the whole. can be written as two factors.

Example: A food contains 81% (by mass) fat.

Percent as a Conversion Factor

1.8 2.2

81%

131

Parts per Million, Parts per Billion

Parts per Million, ppm is the same as mg per kilogram mg/kg of substance.

Parts per Billion, ppb is the same as g per kilogram g/kg of substance.

Example: The maximum dose of lead in pottery glaze is 2 ppm.

132

Chemistry Link to Health

Toxicology and Risk-Benefit Assessment

One measure of toxicity is the LD50 or lethal dose,which is the concentration of the substance thatcauses death in 50% of the test animals.

A dose is typically measured inppm (mg/kg) of bodymass or ppb (μg/kg).

133

Chemistry Link to HealthToxicology and Risk-Benefit Assessment

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134 135135

Learning Check

Write the equality and conversion factors for each of the following.

1. meters and centimeters

2. jewelry that contains 18% gold

3. one liter of gas is $ 0.95

136136

Solution

Write the equality and conversion factors for each of the following.

137137

PROBLEM SOLVING

Chapter 1 §1.9

5:15 PM – 7:20 PM

34

138138

Step 1 Write down what you know on the left hand side of your paper Write down what you want to find on the right hand side of your

paper

Step 2 Create a plan to determine how you will find the answer. Try

working both forwards and backwards to determine your plan

Step 3 Perform the calculations with units to ensure that the calculation

yields the answer you expect form your plan

Step 4 Make sure your answer has the correct number of significant

digits

Steps to Solving Problems

139139

Problem:If a person weighs 164 lb, what is the body mass inkilograms?

Step 1 State the given and needed quantities.Analyze the Problem

Step 2 Write a plan to convert the given unit to the needed unit.

lb US–Metric kilogramsFactor

Steps to Solving Problems (example)

Given Need164 lb kilograms

140140

If a person weighs 164 lb, what is the body mass in kilograms?

Step 3 Work out your calculations and verify the units.

Step 4 Ensure that you have the correct numberof significant digits.

Steps to Solving the Problem 1.83 What is the total mass, in grams, of a

dessert containing 137.25 g of vanilla ice cream, 84 g of fudge sauce, and 43.7 g of nuts?

137.25 g84 g43.7 g

-------.-------264.95 g

265 g

35

1.84 A fish company delivers 22 kg of salmon, 5.5 kg of crab, and 3.48 kg of oysters to your seafood restaurant.

a. What is the total mass, in kilograms, of the seafood?b. What is the total number of pounds?

(Given that 2.20 pounds equals exactly 1 kg.)

22 kg5.5 kg3.48 kg

-------.-------30.98 kg

31 kg

31 ∗ 2.201 68.2

68 lbs

1.85 During a workout at the gym, you set the treadmill at a pace of 55.0 m/min. How many minutes will you walk if you cover a distance of 7500 ft?

(Given that 2.54 cm exactly equals 1 inch.)

42 min

7500 ∗121 ∗

2.541 ∗

1100 ∗

155.0 41.5636363

1.86 Bill’s recipe for onion soup calls for 4.0 lb of thinly sliced onions. If an onion has an average mass of 115 g, how many onions does Bill need?


16 onions

4.0 ∗ 1115 ∗

12.20 ∗

10001 15.8102766798419

1.87 The following nutrition information is listed on a box of crackers:* Serving size 0.50 oz (6 crackers)

* Fat 4 g per serving* Sodium 140 mg per serving

a. If the box has a net weight (contents only) of 8.0 oz, about how many crackers are in the box?

b. If you ate 10 crackers, how many grams of fat did you consume?c. How many grams of sodium are used to prepare 50 boxes of crackers in part a?

(note that 6 is an exact number)

(Note that box is an exact number) 60.50 ∗

8.096

4 1 ∗

16 ∗ 10 6.666

140 ∗11000 ∗

16 ∗

961 ∗ 50 112

96 crackers/box

7 g fat

110 g salt

36

1.88 The price of 1 lb of potatoes is $1.75. If all the potatoes sold today at the store bring in $1,420.00, how many kilograms of potatoes did grocery shoppers buy?


1$1.75 ∗ $1420 ∗

12.20 368.8311688311688

369 kg147

148148

1.89 In Mexico, avocados are 48 pesos per kilogram. What is the cost, in cents, of an avocado that weighs 0.45 lb if the exchange rate is 13.0 pesos to the dollar?


July 2017 60.76 pesos / kgMarch 2018 18.52 pesos / dollar

48∗

$1.0013.0 ∗

100¢$1.00 ∗

12.20 ∗ 0.45 75.52447552447552¢

76¢

37

1.90 An aquarium store unit requires 75,000 mL of water. How many gallons (1 gal = 4 qt) of water are needed?

(Given that 1 gallon equals 3.78541 liters)

75000 ∗ 1

1000 ∗ 1

3.78541 19.81291326434917

20

1.91 a. Some athletes have as little as 3.0% body fat. If such a person has a body mass of 65 kg, how many pounds of body fat does that person have?

b. In a process called liposuction, a doctor removes fat deposits from a person’s body. If body fat has a density of 0.94 g/mL and 3.0 liters of fat are removed, how many pounds of fat were removed from the patient?


65 ∗ 3.0

100 ∗ 2.201 4.29

4.3 lbs

3.0 ∗ 0.94

∗ 1000

∗ 11000 ∗

2.201 6.204

6.2 lbs

1.92 Celeste’s diet restricts her intake of protein to 24 g per day. If she eats an 8.0‐oz burger that is 15.0% protein

a. Has she exceeded her protein limit for the day?

B. How many ounces of a burger would be allowed for Celeste?

(Given that 1 ounce equals 28.3495 grams)

8.0 ∗28.3495

1 ∗15.0 100 34.0194

24 ∗ 1

28.3495 ∗ 100 15.0 5.64383851567047

34 g protein

Yes

5.6 oz burger

153153

DENSITY

Chapter 1 §1.10

5:15 PM – 7:20 PM

38

154154

Which of the following is more dense?

One Pound of One Pound of

154155155

vs

Which Soda is More Dense?

156156

156157157

Density compares the mass of an object to its volume. is the mass of a substance divided by its volume. are measured in g/L for gases. are measured in g/cm3 or g/mL for solids and liquids.

Density expression:

Density

39

158158

Densities of Common Substances

159

Measuring Density of SolidsVolume displacement isthe volume of a solidcalculated from the volumeof water displaced when itis submerged.

160

Measuring Density

Measure the mass of the solid before submerging it in water to determine its volume.

The density of this zinc object is calculated from its mass and volume.

161

Sink or Float

Ice floats in water because the density of ice is less thanthe density of water.

Aluminum sinks in water because its density is greaterthan the density of water.

40

162162

Specific Gravity (sp gr) is the relationship between the density of a

substance and the density of water. is determined by dividing the density of the sample

by the density of water. is a unitless quantity.

Specific Gravity

163163

Specific Gravity is measured by an instrument called a hydrometer.

Specific Gravity

1.93 The water level in a graduated cylinder initially at 215 mL rises to 285 mL after a piece of lead is submerged. What is the mass, in grams, of the lead?

(Given that the density of lead is 11.34 g/ml)

285 215 ∗ 11.34

793.8

790 g

1.94 A graduated cylinder contains 155 mL of water. A 15.0‐g piece of iron and a 20.0‐g piece of lead are added. What is the new water level, in milliliters, in the cylinder?(Given that Iron has a density of 7.874 g/ml and that the density of lead is 11.34 g/ml)

15.0 ∗ 7.874 20.0 ∗ 11.34 155 158.6686722403427

159 ml

41

1.95 Sterling silver is 92.5% silver by mass, with a density of 10.3 g/cm3. If a cube of sterling silver has a volume of 7.0 cm3, how many ounces of pure silver are present?

(Given that 1 ounce equals 28.3495 grams)

7.0 ⁄ ∗ 10.3 ⁄1 ⁄ ∗

92.5 100 ⁄ ∗

128.3495 2.3525

2.4 oz Ag

1.96 A typical adult body contains 55% water. If a person has a mass of 65 kg, how many pounds of water do they have in their body?


65 ∗ 55 100 ∗

2.201 78.65

79 lbs

ENERGY

Chapter 2 §2.1

5:15 PM – 7:20 PM

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