Unit 1 Introduction to Chemistry

Unit 1 Introduction to Chemistry
Outline Unit 1 Introduction to Chemistry PowerPoint Presentation adapted from Mr. John Bergmann

Problems call forth our courage and our wisdom;
indeed, they create our courage and our wisdom. it is only because of problems that we grow mentally and spiritually. It is through the pain of confronting and resolving problems that we learn. M. Scott Peck, b American Psychiatrist and Writer Whether you believe you can do a thing or believe you can’t, you are right. Henry Ford, American Car Manufacturer Don’t be afraid to take a big step if one is indicated. You can’t cross a chasm in two small jumps. David Lloyd George, British Prime Minister and Statesman I use this slide on the first day of class. Students realize that this class will be different. All through my life, the new sights of Nature made me rejoice like a child. Marie Curie, Polish-Born French Chemist Believe that life is worth living, and your belief will help create the fact. William James, American Psychologist and Philospher 2

Chemistry is the study of matter and the transformations it can undergo…
Image courtesy: Introduction to Chemistry 1. What is chemistry? 2. What are the four parts of the scientific method? 3. What is a control experiment? 4. Describe the three types of variables. 5. Compare laws, theories, and hypotheses. 6. What is the only way to prove a hypothesis true? 7. Why do laws and theories evolve? 8. What is the last step of solving any problem? 9. What is measurement? 10. What is a dimension? 11. What is a unit? 12. What is the difference between fundamental and derived units? 13. Why is the standard for mass, in the SI, unique? 14. What is the difference between mass and moles? 15. Is density a fundamental or derived unit? 16. How is a conversion factor made? 17. How is one unit converted to another? 18. What is precision? 19. What do the significant figures of a measurement indicate? 20. In what situation are trailing zeros always significant. 21. Numbers in scientific notation have the basic form A x10B. What is the range of A? 22. What kind of number will have a negative B? 23. Why do scientists use graphs? 24. What variables go on which of the axes of a graph? 25. How do direct and inverse relationships differ? 26. Describe the graph of a direct linear relationship. 27. Describe the graph of an inverse parabolic relationship. 28. What is the slope of a horizontal line? 29. In an experiment the independent variable does not change. What is the slope of the graph? 30. During a lab experiment the temperature of the gas in a balloon is varied and the volume is measured. Which of the two variables will be graphed on the horizontal axis and which will be graphed on the vertical axis? 31. What kind of relationship exists between P and z in this equation? P = mv/z2 3

…Matter is anything that has mass and occupies space.
Chemistry with a Purpose 4

P V H S S P Ar Ta N S The Human Element H He H Li Be B C N O F Ne Na
Interactive Periodic Table P 15 V 23 H 1 S 16 S 16 P 15 Ar 18 Ta 73 N 7 S 16 H 1 He 2 H 1 The Human Element 1 Li 3 Be 4 B 5 C 6 N 7 O 8 F 9 Ne 10 2 Na 11 Mg 12 Al 13 Si 14 P 15 S 16 Cl 17 Ar 18 3 K 19 Ca 20 Sc 21 Ti 22 V 23 Cr 24 Mn 25 Fe 26 Co 27 Ni 28 Cu 29 Zn 30 Ga 31 Ge 32 As 33 Se 34 Br 35 Kr 36 4 Rb 37 Sr 38 Y 39 Zr 40 Nb 41 Mo 42 Tc 43 Ru 44 Rh 45 Pd 46 Ag 47 Cd 48 In 49 Sn 50 Sb 51 Te 52 I 53 Xe 54 5 Cs 55 Ba 56 Hf 72 Ta 73 W 74 Re 75 Os 76 Ir 77 Pt 78 Au 79 Hg 80 Tl 81 Pb 82 Bi 83 Po 84 At 85 Rn 86 6 * A periodic table by itself is not that interesting. It is when we add the "human element", i.e. you and me, that chemistry becomes interesting. And just like that, the laws of chemistry change. A world that includes the Human Element, along with hydrogen, oxygen and other elements, is a very different world indeed. Suddenly, chemistry is put to work solving human problems. Bonds are formed between aspirations and commitments. And the energy released from reactions fuels a boundless spirit that will make the planet a safer, cleaner, more comfortable place for generations to come. A world that welcomes change is about to meet the element of change: the Human Element. By itself, a human body is worth very little (perhaps $5.00 as elements). When we look at the incredible enzymes and hormones in the body we can see we are worth ~millions of dollars. Fr 87 Ra 88 Rf 104 Db 105 Sg 106 Bh 107 Hs 108 Mt 109 7 W La 57 Ce 58 Pr 59 Nd 60 Pm 61 Sm 62 Eu 63 Gd 64 Tb 65 Dy 66 Ho 67 Er 68 Tm 69 Yb 70 Lu 71 Ac 89 Th 90 Pa 91 U 92 Np 93 Pu 94 Am 95 Cm 96 Bk 97 Cf 98 Es 99 Fm 100 Md 101 No 102 Lr 103 5

Earth and Space Science
Natural Science Physical Science Earth and Space Science Life Science Physics Chemistry Geology Astronomy Botany Zoology Meteorology Oceanography Ecology Genetics Science can be broken into social science (social studies, political science, psychology) and natural science. This slides shows some of the diverse areas of natural science. Natural science covers a very broad range of knowledge. Wysession, Frank, Yancopoulos, Physical Science Concepts in Action, 2004, page 4 6

World of Chemistry The Annenberg Film Series
VIDEO ON DEMAND Episode 1 – World of Chemistry The world of chemistry is introduced by providing highlights of key sequences and themes from programs in the series. The relationships of chemistry to the other sciences and to everyday life are presented. Video 01: World of Chemistry The relationships of chemistry to the other sciences and to everyday life are presented. (added 2006/10/08) World of Chemistry > Journey through the exciting world of chemistry with Nobel laureate Roald Hoffman as your guide. The foundations of chemical structures and their behavior are explored through computer animation, demonstrations, and on-site footage at working industrial and research labs. Distinguished scientists discuss yesterday’s breakthroughs and today’s challenged. Produced by the University of Maryland and the Educational Film Center. Released on cassette: Fall The Annenberg/ / CPB Collection LEARNER 8

The Six Levels of Thought
Evaluation The Six Levels of Thought Synthesis Analysis “Success is a journey, not a destination.” -Ben Sweetland Application “Successful students make mistakes, but they don’t quit. They learn from them.” -Ralph Burns Our goal is to be able to do synthesis and evaluation of data. We need to begin with simple fact and knowledge recall and build our way up the cognitive ladder. This requires dedication, memorization, problem-solving and hard work. You will fail at times and must not give up - continue learning and questioning your entire life. Do you think there are "good chemicals" and "bad chemicals"? If so, how do they differ? Chemicals are not "good" or "evil". How we use them determines that. e.g. water to a man that is dehydrating in a desert is good while holding someone under water for too long is evil (drowning them). Comprehension “Success consist of a series of little daily efforts.” -Marie McCuillough Knowledge 9

Job Skills for the Future
Evaluate and Analyze Think Critically Solve Math Problems Organize and Use References Synthesize Ideas Apply Ideas to New Areas Be Creative Make Decisions with Incomplete Information Communicate in Many Modes Some of you may ask the question “Why do I have to study chemistry? I don’t plan to be a chemist when I grow up!” My intention is not to make you into a chemist in one year. I want to explain some of the concepts fundamental to chemistry. This will help to to learn about the world around you – and may even help you later in life. In learning chemistry, you will be required to do many things (listed on the slide). These are skills that you must use in the ‘real-world’ everyday. Your problem solving, math and organizational skills will improve by studying chemistry. Chemistry will develop ALL of these skills in YOU! 10

Dual Perceptions Your experience of learning chemistry maybe somewhat like looking at this picture that tests your perspective. You see either two faces looking at each other or a vase. Sometimes your perception may be that chemistry is challenging, while a short time later your attitude may be that chemistry is easy and fun. You walk into this class having heard stories about it from your friends, siblings or parents that may be similar or different to what you actually experience in the class. They may have had a poor experience in high school chemistry and make you nervous about the class: or they may have had a fantastic experience and you are thrilled to be in my chemistry class. 11

Dual Perceptions Your experience of learning chemistry maybe somewhat like looking at this picture that tests your perspective. Sometimes your perception may be that chemistry is challenging, while a short time later your attitude may be that chemistry is easy and fun. 12

Stack of Blocks This model appear to have three arms. Yet, we know it would be impossible to create an actual object like this picture. Models have limitations - as by their general nature, models are simplifications of complex situations. Yet it is in this simplification that we gain understanding. We need to be careful to not over-simplify and then apply the oversimplification to the real world. 13

What color do the dots appear
What color do the dots appear? All the dots are white and DO NOT change color. Your perception is that they are flickering black / gray / white. 14

This image looks 3-D and appears to waver across the page.
15

Perception of Motion 16

http://www. sapdesignguild
17

A Colorful Demonstration: The Remsen Reaction
Click to see VIDEO Ira Remson ( ) is renowned as one of the most influential American chemists and educators in the 19th century. Demonstration can be found at Metallic Copper + Concentrated Nitric Acid I adapted this lecture experiment from the "Coin-Operated Reaction" developed by Ron Perkins. I have made video records of a few lecture demonstrations, not to replace doing them in class, but rather so students can go back and review the experiments later in the year. I wanted an interesting system with which to make observations on the first day of class. I also wanted to give students an opportunity to explain what they saw in a logical manner. This system is rich with ideas such as gas laws, air pressure, complex ions, oxidizing acids, oxidation reduction, and gas solubility in water. What You Do... To a 500 mL Florence flask, add about 50 mL of concentrated nitric acid. Place a coil of copper wire into the acid and stopper with a one-holed rubber stopper fitted with a long tube. The end of the tube is placed into a large container filled with water. (I use a plastic aquarium.)[1] As soon as the CuO contacts the HNO3(conc) the red-brown NO2(g) forms. What You See... Many changes occur during this demonstration. When the copper wire (or use two pre-1982 pennies) is added to the colorless nitric acid, the solution turns green and a large amount of red-brown gas is formed. The air being displaced by the gas formation can be seen bubbling through the water. The flask gets VERY warm. When enough gas is formed, it bubbles through the water (keep the liquid stirred so most of it will dissolve. The gas that makes it to the top is noxious. When the water siphons back into the flask, the blue Cu(H2O)42+ forms. Later... The gas in the flask begins to cool and therefore contracts. (I am reading my Ira Remsen story and allow students to notice the change.) As the pressure inside the flask decreases, the outside air pressure begins to push the water back toward the original flask. In addition, the red-brown gas dissolves in the water. Eventually, the water rushes into the flask, the solution turns characteristic blue, and the red-brown gas disappears as it is dissolved. The Set Up... Equipment: 500 mL Florence flask ring stand large ring placed below the flask small ring that fits over the neck of the flask one-hole rubber stopper 60 cm glass tubing large container of water The glass tube is bent in such a way as to connect the top of the flask with the bottom of the water container. The water in the container can be stirred by hand or with a magnetic stirrer. It needs to be stirred, however, or else the NO2 gas collects above the liquid (as it did when I took this picture...whew!). The Chemistry... Oxidation of copper metal with a strong oxidizing agent, conc. nitric acid. In a classic experiment, copper metal is turned into copper (II) ion while the nitrogen (V) in the nitrate ion becomes nitrogen (IV) in the nitrogen dioxide gas. Charles' Law As the temperature from the reaction warms the gas, it expands. Later, as it cools, the gas contracts. Nonmetal oxides are acid anhydrides (also link to acid rain) Although the nitrogen dioxide gas is noxious and toxic, it dissolves readily in water and make the solution acidic. This can be shown by adding a little indicator to the water and making the water slightly basic before the copper is added to the acid. Air pressure As the pressure in the flask is decreased as it cools, the outside pressure pushes the water up the tubing toward the flask. The nitrogen dioxide gas is not pulling the water in. Descriptive chemistry--copper solutions are green and blue The colored solutions come from complexes of copper (II) ion in solution. Aqueous copper ion is blue, Cu(H2O)42+ The green must be copper surrounded by nitrates(?) Discussion... THE CHEMISTRY LABORATORY: A LESSON IN SAFETY About 100 years ago, the Chairperson of the Chemistry Department at Johns Hopkins University, and one of the pioneers of chemical education in America, Ira Remsen, wrote the following: (During this demonstration I read the reminiscence by Ira Remson quoted in Bassam Shakhashiri's demonstration book.[2]) While reading a textbook of chemistry I came upon the statement, "nitric acid acts upon copper." I was getting tired of reading such absurd stuff and I was determined to see what this meant. Copper was more or less familiar to me, for copper cents were then in use. I had seen a bottle marked nitric acid on a table in the doctor's office where I was then "doing time." I did not know its peculiarities, but the spirit of adventure was upon me. Having nitric acid and copper, I had only to learn what the words "act upon" meant. The statement "nitric acid acts upon copper" would be more than mere words. All was still. In the interest of knowledge I was even willing to sacrifice one of the few copper cents then in my possession. I put one of them on the table, opened the bottle marked nitric acid, poured some of the liquid on the copper and prepared to make an observation. But what was this wonderful thing which I beheld? The cent was already changed and it was no small change either. A green-blue liquid foamed and fumed over the cent and over the table. The air in the neighborhood of the performance became colored dark red. A great colored cloud arose. This was disagreeable and suffocating. How should I stop this? I tried to get rid of the objectionable mess by picking it up and throwing it out of the window. I learned another fact. Nitric acid not only acts upon copper, but it acts upon fingers. The pain led to another unpremeditated experiment. I drew my fingers across my trousers and another fact was discovered. Nitric acid acts upon trousers. Taking everything into consideration, that was the most impressive experiment and relatively probably the most costly experiment I have ever performed... It was a revelation to me. It resulted in a desire on my part to learn more about that remarkable kind of action. Plainly, the only way to learn about it was to see its results, to experiment, to work in a laboratory.[3] The description above is very amusing and expresses an enthusiasm for chemistry that we all should strive for. Ira Remsen also recognized the vital importance of the laboratory experience in chemistry. However, he was very fortunate that this particular experiment did not have dire consequences. Experiments should never be conducted using the methods described. List all the violations of good safety practice in the experiment described by Ira Remsen and suggest some safer approaches to finding out what was meant by the words "acts upon". Safety and Disposal... The solution is highly acidic. I pour it out into a large beaker or battery jar and add excess sodium carbonate. The carbon dioxide bubbles indicate neutralization and the resulting copper carbonate precipitate is filtered, placed in a baggie and thrown away. The neutralized filtrate can be disposed of as you would any simple salt solution. Procedures may vary from location to location. References: [1] This demonstration is based on one shown by Ron Perkins called the "Coin Operated Demonstration" [2] Shakhishiri, B.Z. "Chemical Demonstrations Volume 1--A Handbook for Teachers of Chemistry"; The University of Wisconsin Press: Madison, Wisconsin, 1983 [3] Getman, F.H. "The Life of Ira Remsem"; Journal of Chemical Education: Easton, Pennsylvania, 1940; pp9-10. A Colorful Demonstration: The Remsen Reaction 18

Safety

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

Safety Features of the Lab
safety shower fire blanket fire extinguisher eye wash fume hood circuit breaker switch

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

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

Government Regulation of Chemicals
The government regulates chemicals to reduce the risk to the… Consumer FDA, USDA, Consumer Product Safety Commission Worker GOVERNMENT REGULATION OF CHEMICALS Thalidomide was a drug given to lessen the effects of morning sickness to pregnant woman in the 1960’s. It never was proven safe and effective (efficacy) to the Food and Drug Administration in the United States. Only two cases of birth defects, thalidomide related, were reported in the United States. The women who had the children with the truncated limb formation were “jet setters” and obtained the thalidomide over seas. Internet Access to the Center for Disease Control, CDC, and the Food and Drug Administration, FDA There is a tremendous amount of trivial information on the Internet. It also provides a direct, quick connection to government agencies and other sources of hard factual information. This is an exercise in using the Internet to learn about the power of the Internet. Simultaneously, you will have an opportunity to learn what health agencies like the FDA and the CDC say about health risks and smoking. The Internet pages typically have interactive or “hot” buttons. The most common interactive spots are underlined text items. Sometimes there are images that are buttons. Usually they are identified with “Click here” messages. You can’t go wrong by clicking on an item to find out if is active. ONE CAUTION, there is a time delay between the time you click and the time when the system responds and connects you. You need some patience here. Computers have gotten faster, but people are asking the computer to do more. You probably already know you can’t rush the machines. This is a chance to surf the net. Go ahead; get your feet wet. THE CDC home page and the FDA Public agencies like the Center for Disease Control, CDC, and the Food and Drug Administration, FDA, can be accessed through the Internet. The CDC page on tobacco risks can be reached by using the following uniform resource locator (URL). Your assignment is to open this page. The site will give you data to answer the questions on the report sheet. OVERVIEW Your are to find out what the CDC says about the number of deaths annually in the United States that are said to be caused by smoking. In addition, you are to open the active line that gives the Food and Drug Administration’s proposed regulations on tobacco by clicking on the underlined FDA entry. If you have trouble, you can use the following URL for the FDA site. Your are supposed to record your opinion of the FDA proposals on tobacco regulation and give a reason for your opinion. Name _____________________________________ Hour _____ Date _________ Use the following URL to answer these questions. What is the Center for Disease Control’s estimate of the number of deaths in the United States that are annually caused by tobacco? Does this seem like a large number to you? Why? Use the following URL to answer this question. What is your opinion of the regulations proposed by the FDA? Would you endorse these proposals? Explain. Give the URL for a interesting site you found while doing this exercise. What makes this site noteworthy? Internet Access to the Environmental Protection Agency, EPA Health Risk: EPA Office of Air and Radiation, OAR The issue of health risk and air pollution concerns all of us. Frequently people assume that air pollution is only a problem in big cities like New York city or Los Angeles. It may come as a surprise, but even cities in the Rock Mountains have air pollution problems. The Environmental Protection Agency, EPA, provides some basic information about risks ar the URL given in this exercise. The EPA page on Air Pollution and Health Risk The EPA page on Air Pollution and Health Risk can be reached using the following uniform resource locator (URL). You can find answers to the following questions at this URL. What are the attributes of risks that are classes as more serious and of greatest concern? What are the attributes of risks that are classes as less serious and of lesser concern? According to the EPA Health Risk is the probability, or chance that exposure to a hazardous substance will make you sick. What are the two factors that are used to estimate risk? What actions does the EPA recommend to reduce your exposure to hazards? OSHA Environment EPA Chemical Stewardship 24

Chemical Burns Skin burned by chemicals Chemical burns on feet.
Flammable Reactive Health Special Chemical Burns Chemical burns on feet. Skin burned by chemicals 25

SAFETY in the Science Classroom
Obey the safety contract Use common sense No unauthorized experiments Wear safety glasses Safety is an attitude! Don’t take anything out of lab Read and follow all instructions Go over Safety Contract with students. Link for copy of safety contract: 26

LD50 the lethal dosage for 50% of the animals on which the chemical is tested There are various ways an LD50 can be expressed. For example, acetone has the following LD50s: ORL-RAT LD50: 5,800 mg/kg IHL-RAT LD50: 50,100 mg/m3-h SKN-RBT LD50: 20 g/kg

Example Chemical A: LD50 = 3.2 mg/kg Chemical B: LD50 = 48 mg/kg
Which is more toxic? Chemical A is more toxic because less of it proves fatal to half of a given population.

Science

The Functions of Science
pure science applied science the search for knowledge; facts using knowledge in a practical way e.g., aluminum strong lightweight good conductor

Science attempts to establish cause-effect relationships.


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

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

The Scientific Method

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

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

Parts of the Scientific Method
Identify an unknown. Make a hypothesis: a testable prediction Repeatedly experiment to test hypothesis. procedure: order of events in experiment (i.e., a recipe) variable: any factor that could influence the result

A Scientific Experiment
Experiments must be controlled: they must have two set-ups that differ by only one variable conclusion: must be based on the data

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

Phlogiston Theory of Burning
1. Flammable materials contain phlogiston. 2. During burning, phlogiston is released into the air. 3. Burning stops when… …object is out of phlogiston, or …the surrounding air contains too much phlogiston. (superceded by combustion theory of burning)

Chemistry

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

Allegedly, this substance would turn cheap metals into gold.
Alchemy (~500 – 1300 C.E.) the quest for the Philosopher’s Stone (the elixir, the Sorcerer’s Stone) Allegedly, this substance would turn cheap metals into gold. Alchemical symbols for substances… . . . . . . GOLD SILVER COPPER IRON SAND

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

Alchemy was practiced in many regions of the
world, including China and the Middle East. Alchemy arrived in western Europe around the year 500 C.E. Modern chemistry evolved from alchemy.

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

What is Chemistry? the study of matter and its changes

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

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

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

The Scope of Chemistry bulk chemical manufacturing
acids, bases, fertilizers **sulfuric acid (H2SO4) = #1 chemical petroleum products fuels, oils, greases, asphalt pharmaceuticals 1 in 10,000 new products gets FDA approval synthetic fibers nylon, polyester, rayon , spandex

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

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

Manipulating Numerical Data

Graphs

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

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

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

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

Essential Math of Chemistry

Scientific Notation -- used to express very large or very small numbers, and/or to indicate precision (i.e., to maintain the correct number of significant figures) Form: (# from 1 to 9.999) x 10exponent 800 = 8 x 10 x 10 = 8 x 102 2531 = x 10 x 10 x 10 = x 103 = = 1.4 x 10–3

Put in standard form. 1.87 x 10–5 = 3.7 x 108 = 370,000,000 7.88 x 101 = 78.8 2.164 x 10–2 = Change to scientific notation. 12,340 = x 104 0.369 = 3.69 x 10–1 0.008 = 8 x 10–3 1,000,000,000 = 1 x 109 6.02 x 1023 = 602,000,000,000,000,000,000,000

Using the Exponent Key EXP EE

The EE or EXP or E key means “times 10 to the…”
How to type out 6.02 x 1023: How to type out 6.02 x 1023: 6 EE . 3 2 6 EE . 3 2 not… WRONG! 6 y x . 3 2 WRONG! or… x 1 6 . 2 EE 3 and not… TOO MUCH WORK. y x 3 2 x 1 6 .

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

1.2 x 105 2.8 x 1019 = 1 . 2 EE 5 9 8 Type this calculation in like this: –15 Calculator gives… E–15 or… This is NOT written… 4.3–15 But instead is written… 4.3 x 10–9 or 4.3 E –9

7.5 x 10–6 (–8.7 x 10–14) = –6.5 x 10–19 4.35 x 106 (1.23 x 10–3) = 5.35 x 103 or 5350 5.76 x 10– x 10–4 = 5.84 x 10–13 8.8 x 1011 x 3.3 x 1011 = 2.9 x 1023

Essential Math of Chemistry

Units must be carried into the
answer, unless they cancel. 5.2 kg (2.9 m) (18 s)(1.3 s) = kg-m s2 0.64 4.8 kg (23 s) (18 s)(37 s) = kg s 0.57

x + y = z x + y = z – y – y x = z – y Solve for x.
x and y are connected by addition. Separate them using subtraction. In general, use opposing functions to separate things. x + y = z – y – y The +y and –y cancel on the left, x = z – y leaving us with…

Numerical Example x – 24 = 13 x – 24 = 13 +24 +24 x = 37 Solve for x.
x and 24 are connected by subtraction. Separate them using the opposite function: addition. x – 24 = 13 +24 +24 The –24 and +24 cancel on the left, leaving us with… x = 37

( ) F = k x __ 1 k F = k x (or) F = k x k x = F k __ Solve for x.
x and k are connected by multiplication. Separate them using the opposite function: division. (or) F = k x k The two k’s cancel on the right, leaving us with… x = F k __

( ) Numerical Example 8 = 7 x __ 1 7 8 = 7 x (or) 8 = 7 x 7 x = 8 7 __
Solve for x. 8 = 7 x ( ) __ 1 7 8 = 7 x x and 7 are connected by multiplication. Separate them using the opposite function: division. (or) 8 = 7 x 7 The two 7’s cancel on the right, leaving us with… x = 8 7 __

( ) ___ x BA = TR H BAH = xTR 1 TR ___ BAH = xTR ___ BAH TR x =
Solve for x. ___ x BA = TR H One way to solve this is to cross-multiply. BAH = xTR 1 TR ( ) ___ Then, divide both sides by TR. BAH = xTR ___ BAH TR x = The answer is…

( ) ____ T1 P1V1 = P2V2 T2 1 ____ P1V1T2 = P2V2T1 T2 = P1V1 ______
Solve for T2, where… P1 = 1.08 atm P2 = 0.86 atm V1 = 3.22 L V2 = 1.43 L T1 = 373 K ____ T1 P1V1 = P2V2 T2 1 P1V1 ( ) ____ P1V1T2 = P2V2T1 T2 = P1V1 ______ P2V2T1 T2 = (1.08 atm)(3.22 L) _____________________ (0.86 atm)(1.43 L)(373 K) = 132 K

SI Prefixes kilo- (k) 1000 deci- (d) 1/10 centi- (c) 1/100
milli- (m) 1/1000 Also, 1 mL = 1 cm3 and 1 L = 1 dm3

Conversion Factors and Unit Cancellation

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

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

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

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

Simple Math with Conversion Factors

( ) ( ) ______ ______ Find area of rectangle. A = L . W 4.6 cm
= (4.6 cm)(9.1 cm) 9.1 cm = 42 cm 2 . cm cm.cm ( ) ______ 100 cm 1 m Convert to m2. 42 cm2 2 = m2 ( ) ______ 1 cm 10 mm Convert to mm2. 42 cm2 2 = mm2

For the rectangular solid:
Length = 14.2 cm Width = 8.6 cm Height = 21.5 cm Find volume. V = L . W . H = (14.2 cm)(8.6 cm)(21.5 cm) = 2600 cm3

( ) ______ Convert to mm3. 1 cm 10 mm 2600 cm3 3 = 2,600,000 mm3
= x 106 mm3 mm and cm differ by a factor of………. mm2 “ cm2 “ “ “ “ “ ………. mm3 “ cm3 “ “ “ “ “ ………. 10 100 1000

Basic Concepts in Chemistry

“what you started with”
chemical: any substance that takes part in, or occurs as a result of, a chemical reaction All matter can be considered to be chemicals or mixtures of chemicals. chemical reaction: a rearrangement of atoms such that… “what you end up with” differs from “what you started with” products reactants

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

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

Law of Conservation of Mass
total mass total mass of products of reactants = Pmass = Rmass synthesis: taking small molecules and putting them together, usually in many steps, to make something more complex JENNY

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

KEYS - Intro. to Chemistry
Worksheet - vocabulary Worksheet - material safety data sheet (acetone) Activity - checkbook activity Worksheet - graphing Worksheet - real life chemistry Worksheet - conversion factors Worksheet - scientific notation Worksheet - metric article (questions) Worksheet - significant digits Worksheet - math review Worksheet - math of chemistry Worksheet - article on the metric system Textbook - questions Lab – introduction to qualitative analysis Outline (general)

Resources - Intro. to Chemistry
Worksheet - vocabulary Worksheet - material safety data sheet (acetone) Activity - checkbook activity Worksheet - graphing Worksheet - real life chemistry Worksheet - conversion factors Worksheet - scientific notation Worksheet - metric article (questions) Video 01: World of Chemistry The relationships of chemistry to the other sciences and to everyday life are presented. (added 2006/10/08) World of Chemistry > Video 03: Measurement: the Foundation of Chemistry The distinction between accuracy and precision and its importance in commerce and science are explained. (added 2006/10/08) World of Chemistry > Video 04: Modeling the Unseen Models are used to explain phenomena that are beyond the realm of ordinary perception. (added 2006/10/08) World of Chemistry > Journey through the exciting world of chemistry with Nobel laureate Roald Hoffman as your guide. The foundations of chemical structures and their behavior are explored through computer animation, demonstrations, and on-site footage at working industrial and research labs. Distinguished scientists discuss yesterday’s breakthroughs and today’s challenged. Produced by the University of Maryland and the Educational Film Center. Released on cassette: Fall The Annenberg/ / CPB Collection LEARNER Episode 1 - The World of Chemistry Worksheet - significant digits Episode 3 – Measurement: The Foundation of Chemistry Worksheet - math review Episode 4 - Modeling The Unseen Worksheet - math of chemistry Worksheet - article on the metric system Textbook - questions Lab – introduction to qualitative analysis Outline (general)

Unit 1 Introduction to Chemistry

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Unit 1 Introduction to Chemistry

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