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Chemistry is the study of matter and the transformations it can undergo

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Matter is anything that occupies space.

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The Six Levels of Thought Knowledge Comprehension Application Analysis Synthesis Evaluation Success is a journey, not a destination. -Ben Sweetland Successful students make mistakes, but they dont quit. They learn from them. -Ralph Burns Success consist of a series of little daily efforts. -Marie McCuillough

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Basic Safety Rules Use common sense. No unauthorized experiments. No horseplay. Handle chemicals/glassware with respect.

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

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

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Chemical Exposure a one-time exposure causes damage acute exposurechronic exposure damage occurs after repeated exposure

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Toxicity Which is more toxic? Chemical A: LD 50 = 3.2 mg/kg Chemical B: LD 50 = 48 mg/kg Chemical A is more toxic because less of it proves fatal to half of a given population.

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The Functions of Science pure scienceapplied science the search for knowledge; facts using knowledge in a practical way

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Pure Science The search for facts about the natural world. ? - In science, we often try to establish a cause-effect relationship. - Driven by curiosity: the need to know, explore, conquer something new.

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Fundamental Properties of Models A model does not equal reality. Models are oversimplifications, and are therefore often wrong. Models become more complicated as they age. We must understand the underlying assumptions in a model so that we dont misuse it.

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Using the scientific method requires that one be a good observer. observationinference involves a judgment or assumption uses the five senses

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Data Observations are also called data. There are two types of data. qualitative dataquantitative data descriptions; measurements; no numbersmust have numbers and UNITS

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Parts of the Scientific Method Identify an unknown. Make a hypothesishypothesis (a testable prediction). Experiment to testExperiment the hypothesis. Draw a valid conclusion.

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Hypotheses A tentative explanation for the observations May not be correct, but it puts the scientists understanding of the system being studied into a form that can be tested Copyright 2007 Pearson Benjamin Cummings. All rights reserved.

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Experiments Tests the validity of the hypothesis Are systematic observations or measurements made under controlled conditions, in which the variable of interest is clearly distinguished from any others If experimental results are reproducible, they are summarized in a law. Copyright 2007 Pearson Benjamin Cummings. All rights reserved.

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A Scientific Experiment procedure the order of events in an experiment; the recipe Experiments must be controlled; they must have two set-ups that must differ by only one variable. The conclusion must be based on the data. variable any factor that could influence the result

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Scientific Method Observations Hypothesis Experimentation Controlled (one variable changed at a time) Collect data (quantitative and qualitative) Analyze data (graph, statisticstrends) Form valid conclusion. After many experimentsform a theory.

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Fundamental Properties of Models A model does not equal reality. Models are oversimplifications, and are therefore often wrong. Models become more complicated as they age. We must understand the underlying assumptions in a model so that we dont misuse it.

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Scientific Law vs. Scientific Theory Law of Gravity A theory tries to explain why or how something happens. A law states what happens. Theory of Gravity Atomic Theory Collision Theory of Reactions

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Experiments Law A verbal or mathematical description of a phenomenon that allows for general predictions Describes what happens and not why Unlikely to change greatly over time unless a major experimental error is discovered Theory Attempts to explain why nature behaves as it does Is incomplete and imperfect, evolving with time to explain new facts as they are discovered Copyright 2007 Pearson Benjamin Cummings. All rights reserved.

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Make observation Ask question Develop hypothesis Develop hypothesis Test hypothesis with an experiment Test hypothesis with an experiment Analyze data and draw conclusions Analyze data and draw conclusions Hypothesis IS supported Hypothesis IS supported Hypothesis is NOT supported Hypothesis is NOT supported Develop theory Develop theory Test hypothesis with further experiments Test hypothesis with further experiments Revise hypothesis Revise hypothesis Wysession, Frank, Yancopoulos, Physical Science Concepts in Action, 2004, page 8 Scientific Method

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Then And Question Research Hypothesis Procedure/ Method Procedure/ Method Data Observations Conclusion What does the scientist want to learn more about? What does the scientist want to learn more about? Gathering of information An Educated guess of an answer to the question An Educated guess of an answer to the question Written and carefully followed step-by-step experiment designed to test the hypothesis Written and carefully followed step-by-step experiment designed to test the hypothesis Information collected during the experiment Information collected during the experiment Written description of what was noticed during the experiment Written description of what was noticed during the experiment Was the hypothesis correct or incorrect? Was the hypothesis correct or incorrect? Next Then Next And Finally First Scientific Method An Overview

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Phlogiston Theory (a) When an object burns it gives off a substance called phlogiston. (b) When the space surrounding the burning object is filled with phlogiston, the object will no longer be able to burn. Phlogiston theory of burning Dorin, Demmin, Gabel, Chemistry The Study of Matter, 3 rd Edition, 1990, page 4 phlogiston (a) (b)

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Combustion Theory Modern theory of burning (c) When an object burns, it uses up a substance (oxygen) in the surrounding space. (d)When the space surrounding the burning object has too little oxygen in it, the object will no longer be able to burn. Antoine Lavoiser Dorin, Demmin, Gabel, Chemistry The Study of Matter, 3 rd Edition, 1990, page 4 oxygen (c) (d)

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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.

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Laboratory Equipment

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Copper was used to make bullet shells in WW II. By 1943, the supply of copper metal was in short supply. The US government did not want to waste copper on making pennies. Pennies were made with steel metal. They looked silver. Zinc Pennies Before 1982, all pennies were solid copper (except 1943). After 1982, pennies were made from zinc. A thin coating of copper was pressed on the zinc. A shortage of copper drove the price of copper up in the early 1980s. If melted down, the copper could be sold for more than one cent.

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transmutation In ordinary chemical reactions, we cannot transmute elements into different elements. changing one substance into another COPPER GOLD Philosophers Stone

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

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

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Measurements Numbers science is based on measurements all measurements have: - magnitude - uncertainty - units mathematics is based on numbers exact numbers are obtained by: - counting - definition

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Graphs Line Graph Used to show trends or continuous change Bar Graph Used to display information collected by counting Pie Graph Used to show how some fixed quantity is broken down into parts

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Convert 41.2 cm 2 to m 2. 100 cm 1 m () ______ X m 2 = 41.2 cm 2 X m 2 = 41.2 cm. cm Recall that41.2 cm 2 = 41.2 cm. cm 100 cm 1 m () ______ X m 2 = 41.2 cm 2 =0.412 m 2 =0.412 cm. m WRONG! () ______ 100 cm 1 m =0.00412 m 2 () ______ 100 cm 1 m 2 =0.00412 m 2

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Convert 41.2 cm 2 to mm 2. X mm 2 = 41.2 cm 2 X mm 2 = 41.2 cm. cm Recall that41.2 cm 2 = 41.2 cm. cm 1 cm 10 mm () _____ =4,120 mm 2 = 1 cm 10 mm () _____ 4,120 mm 2 1 cm 10 mm 2 () _____

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Measured dimensions of a rectangular solid: Find volume of solid. L W H Length = 15.2 cm Width = 3.7 cm Height = 8.6 cm V = L. W. H = (15.2 cm)(3.7 cm)(8.6 cm) =480cm 3

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Convert to m 3. X m 3 = 480 cm 3 =0.000480 m 3 100 cm 1 m 3 () _____ X m 3 = 480 cm 3 = X m 3 = 480 100 cm 1 m () _____ 100 cm 1 m () _____ 100 cm 1 m () _____ = or cm. cm. cm 1 m 1000000 cm ( ) _________ 3 3 4.80 x 10 -4 m 3 or 3 2 cm

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Measured dimensions of a rectangular solid: Find volume of solid. L W H Length = 15.2 cm Width = 3.7 cm Height = 8.6 cm V = L. W. H = (0.152 m)(0.037 m)(0.086 m) =0.000480 m 3 0.152 m 0.037 m 0.086 m Convert to m 3...

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Convert to mm 3.

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= -6.525 x 10 -9 = 5.3505 x 10 3 or 5350.5 = 5.84178499 x 10 -13 report -6.5 x 10 -9 (2 sig. figs.) report 5.35 x 10 3 (3 sig. figs.) report 5.84 x 10 -13 (3 sig. figs.) = 2.904 x 10 23 report 2.9 x 10 23 (2 sig. figs.) = -3.07122 x 10 16 report -3.1 x 10 16 (2 sig. figs.)

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Rule for Multiplication Calculating with Numbers Written in Scientific Notation When multiplying numbers in scientific notation, multiply the first factors and add the exponents. Sample Problem: Multiply 3.2 x 10 -7 by 2.1 x 10 5 (3.2) x (2.1) = 6.72 (-7) + (5) = -2 or 10 -2 6.72 x 10 -2 Exercise: Multiply 14.6 x 10 7 by 1.5 x 10 4 2.19 x 10 12

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Rule for Division Calculating with Numbers Written in Scientific Notation When dividing numbers in scientific notation, divide the first factor in the numerator by the first factor in the denominator. Then subtract the exponent in the denominator from the exponent in the numerator. Sample Problem: Divide 6.4 x 10 6 by 1.7 x 10 2 (6.4) (1.7) = 3.76 (6) - (2) = 4 or 10 4 3.76 x 10 4 Exercise: Divide 2.4 x 10 -7 by 3.1 x 10 14 7.74 x 10 -22..

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Rule for Addition and Subtraction Calculating with Numbers Written in Scientific Notation In order to add or subtract numbers written in scientific notation, you must express them with the same power of 10. Sample Problem: Add 5.8 x 10 3 and 2.16 x 10 4 (5.8 x 10 3 ) + (21.6 x 10 3 ) =27.4 x 10 3 Exercise: Add 8.32 x 10 -7 and 1.2 x 10 -5 1.28 x 10 -5 2.74 x 10 4

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Using Scientific Notation for Expressing the Correct Number of Significant Figures Measurement Number of significant figures it contains Measurement Number of significant figures it contains 25 g 0.030 kg 1.240560 x 10 6 mg 6 x 10 4 sec 246.31 g 20.06 cm 1.050 m 0.12 kg 1240560. cm 6000000 kg 6.00 x 10 6 kg 409 cm 29.200 cm 0.02500 g 2 2 7 1 5 4 4 2 7 1 3 3 5 4

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chemical reaction a rearrangement of atoms such that what you end up withproducts differs from what you started withreactants

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methane + oxygen + H 2 O(g) carbon dioxide O 2 (g)CO 2 (g)CH 4 (g)+ water+ 22 Combustion of a Hydrocarbon

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NaOH(aq) water Na(s)H 2 O(l)H2(g)H2(g)2 sodium 22 hydrogen sodium hydroxide + + + +

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Synthesis taking small molecules and putting them together, usually in many steps, to make something more complex Photosynthesis Sunlight Carbon Dioxide Water Oxygen Glucose CO 2 + H 2 O O 2 + C 6 H 12 O 6

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The International System of Units Lengthmeter m Masskilogram kg Timesecond s Amount of substancemole mol Thermodynamic temperatureKelvin K Electric currentamperes amps Luminous intensitycandela cd QuantityNameSymbol Dorin, Demmin, Gabel, Chemistry The Study of Matter, 3 rd Edition, 1990, page 16

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Derived Units Commonly Used in Chemistry Areasquare meter m 2 Volumecubic meter m 3 Forcenewton N Pressurepascal Pa Energyjoule J Powerwatt W Voltagevolt V Frequencyhertz Hz Electric chargecoulomb C Quantity Name Symbol

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Area and Volume: Derived Units Area = length x width = 5.0 m x 3.0 m = 15 ( m x m) = 15 m 2 Volume = length x width x height = 5.0 m x 3.0 m x 4.0 m = 60 ( m x m x m) = 60 m 3

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Prefixes in the SI System Power of 10 for Prefix SymbolMeaning Scientific Notation _______________________________________________________________________ mega-M 1,000,00010 6 kilo-k 1,00010 3 deci-d 0.110 -1 centi-c 0.0110 -2 milli-m 0.00110 -3 micro- 0.00000110 -6 nano-n 0.00000000110 -9 The Commonly Used Prefixes in the SI System Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 118

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Quantities of Mass Kelter, Carr, Scott, Chemistry A Wolrd of Choices 1999, page 25 Earths atmosphere to 2500 km Ocean liner Indian elephant Average human 1.0 liter of water Grain of table salt Typical protein Uranium atom Water molecule 10 24 g 10 21 g 10 18 g 10 15 g 10 12 g 10 9 g 10 6 g 10 3 g 10 0 g 10 -3 g 10 -6 g 10 -9 g 10 -12 g 10 -15 g 10 -18 g 10 -21 g 10 -24 g Giga- Mega- Kilo- base milli- micro- nano- pico- femto- atomo-

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SI-US Conversion Factors RelationshipConversion Factors Length Volume Mass 2.54 cm = 1 in. 1 m = 39.4 in. 946 mL = 1 qt 1 L = 1.06 qt 454 g = 1 lb 1 kg = 2.20 lb 1 in 2.54 cm 39.4 in 1 m 39.4 in. 946 mL 1 qt 946 mL 1.06 qt 1 L 1.06 qt 454 g 1 lb 454 g 2.20 lb 1 kg 2.20 lb 2.54 cm 1 in and

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Accuracy vs. Precision Random errors: reduce precision Good accuracy Good precision Poor accuracy Good precision Poor accuracy Poor precision Systematic errors: reduce accuracy (person)(instrument)

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Precision Accuracy reproducibility check by repeating measurements poor precision results from poor technique correctness check by using a different method poor accuracy results from procedural or equipment flaws.

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Errors Systematic Errors in a single direction (high or low) Can be corrected by proper calibration or running controls and blanks. Random Errors in any direction. Cant be corrected. Can only be accounted for by using statistics.

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Accuracy Precision Resolution subsequent samples time offset [arbitrary units] not accurate, not precise accurate, not precise not accurate, precise accurate and precise accurate, low resolution -2 -3 0 1 2 3

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SI Prefixes kilo-1000 deci- 1 / 10 centi- 1 / 100 milli- 1 / 1000 Also know 1 mL = 1 cm 3 and 1 L = 1 dm 3

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SI System for Measuring Length Unit Symbol Meter Equivalent _______________________________________________________________________ kilometerkm 1,000 m or 10 3 m meter m 1 m or 10 0 m decimeterdm 0.1 m or 10 -1 m centimetercm 0.01 m or 10 -2 m millimetermm 0.001 m or 10 -3 m micrometer m 0.000001 m or 10 -6 m nanometernm 0.000000001 m or 10 -9 m The SI Units for Measuring Length Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 118

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Practice Measuring 4.5 cm 4.54 cm 3.0 cm Timberlake, Chemistry 7 th Edition, page 7 cm 0 12345 0 12345 0 12345

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Implied Range of Uncertainty 5 64 3 Implied range of uncertainty in a measurement reported as 5 cm. 5 64 3 Implied range of uncertainty in a measurement reported as 5.0 cm. Dorin, Demmin, Gabel, Chemistry The Study of Matter 3rd Edition, page 32 5 64 3 Implied range of uncertainty in a measurement reported as 5.00 cm.

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750 740 760 Here is a final example, with the vernier at yet another position. The pointer points to a value that is obviously greater than 751.5 and also less than 752.0. Looking for divisions on the vernier that match a division on the scale, the 8 line matches fairly closely. So the reading is about 751.8. In fact, the 8 line on the vernier appears to be a little bit above the corresponding line on the scale. The 8 line on the vernier is clearly somewhat below the corresponding line of the scale. So with sharp eyes one might report this reading as 751.82 0.02. This "reading error" of 0.02 is probably the correct error of precision to specify for all measurements done with this apparatus. 5 0 10 http://www.upscale.utoronto.ca/PVB/Harrison/Vernier/Vernier.html

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How to Read a Thermometer (Celcius) 10 5 0 4.0 o C 10 5 0 8.3 o C 100 50 0 64 o C 5 0 3.5 o C

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0oC0oC 10 o C 20 o C 30 o C 40 o C 50 o C 60 o C 0oC0oC 1oC1oC 2oC2oC 3oC3oC 4oC4oC 5oC5oC 6oC6oC 0oC0oC 5oC5oC 10 o C 15 o C 20 o C 25 o C 0oC0oC 20 o C 40 o C 60 o C 80 o C 100 o C 0oC0oC 20 o C 40 o C 60 o C 80 o C 100 o C Record the Temperature (Celcius) A B C D E 30.0 o C 3.00 o C19.0 o C 48 o C 60. o C

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Rules for Counting Significant Figures 1. Nonzero integers always count as significant figures. 2. Zeros: There are three classes of zeroes. a.Leading zeroes precede all the nonzero digits and DO NOT count as significant figures. Example: 0.0025 has ____ significant figures. b.Captive zeroes are zeroes between nonzero numbers. These always count as significant figures. Example: 1.008 has ____ significant figures. c.Trailing zeroes are zeroes at the right end of the number. Trailing zeroes are only significant if the number contains a decimal point. Example: 1.00 x 10 2 has ____ significant figures. Trailing zeroes are not significant if the number does not contain a decimal point. Example: 100 has ____ significant figure. 3.Exact numbers, which can arise from counting or definitions such as 1 in = 2.54 cm, never limit the number of significant figures in a calculation. 2 4 3 1 Ohn-Sabatello, Morlan, Knoespel, Fast Track to a 5 Preparing for the AP Chemistry Examination 2006, page 53

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Significant figures: Rules for zeros Leading zeros are not significant. Captive zeros are significant. Trailing zeros are significant. Leading zero Captive zero Trailing zero 0.421 4012 114.20 three significant figures four significant figures five significant figures

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Significant Figures Number of QuantityCertainUncertainSignificant DigitsDigitsFigures 14.379 g1 4 3 7 9 (thousandths) 5 6.02 mL6 0 2 (hundredths) 3 120.580 m1 2 0 5 8 0 (thousandths) 6 7.5 g7 5 (tenths) 2 0.037 g3 7 (thousandths) 2 0.0370 g3 7 0 (ten-thousandths) 3 *The position of the decimal point has nothing to do with the number of significant figures. Ralph A. Burns, Fundamentals of Chemistry 1999, page 52

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___ BAH TR x = Basic Algebra Solve for x. ___ x BA = TR H ___ BAH = xTR One way to solve this is to cross-multiply. BAH = xTR Then, divide both sides by TR. The answer is 1 TR () ___1 TR () ___

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Solve for T 2, where P 1 = 1.08 atm P 2 = 0.86 atm V 1 = 3.22 L V 2 = 1.43 L T 1 = 373 K P 1 V 1 T 2 = P 2 V 2 T 1 ____ T1T1 P1V1P1V1 = P2V2P2V2 T2T2 1 P1V1P1V1 () 1 P1V1P1V1 () T 2 = P1V1P1V1 ______ P2V2T1P2V2T1 130 T 2 = (1.08 atm)(3.22 L) _____________________ (0.85 atm)(1.43 L)(373 K) = K

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A General Procedure for Solving Problems Read the problem carefully and make a list of the knowns and the unknowns Look up all needed information YYour lecture notes will have much, if not all, of the needed information Work out a plan and, following your plan, obtain an answer by carrying out the required math. Check over your work TThis is best done by estimating your answer AAsk yourself: Does the answer seem reasonable?

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How to Succeed in Chemistry Learn the language Use the illustrations Review your notes frequently Work as many problems as possible Do NOT cram for exams.