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An easy question, or two: When is the first exam? 1.October 26 2.Sept 26 3.Probably next Monday 4.We don’t have exams in this class; everyone gets an A. When is the first quiz? 1.October 26 2.Sept 26 3.Probably next Monday 4.We don’t have quizzes in this class; everyone gets an A.

How to do well in the class

Chemistry passport Name Education: where you went to high school Reasons why you are taking the course What you want to get out of the course Major (or possible major if undecided) and minor Hobbies One thing that you are very good at! Hurricane: –Home address, home phone –Cell phone, dorm #, RA

Chemistry passport David Hastings Education: –Newton North High School, Newton, Mass. –Princeton University, chemistry, cum laude –University of Washington, PhD. chemical oceanography Reasons why I am teaching this course: –As a chemical oceanographer, I use chemistry every day. I want to teach chemistry so that students understand why it might be useful to them, and realize that first year chemistry can be interesting and fun. –What I want to get out of this course: for students to: understand chemical concepts + principles to provide real examples from marine science when possible. to develop students' problem-solving and critical thinking skills Major: Marine Science and Chemistry Hobbies: kayaking, telemark skiing, bicycling, swimming, dancing, community activism. I am very good at: contra dancing / skiing

Chemistry passport David Hastings Education: –Newton North High School, Newton, Mass. –Princeton University, chemistry, cum laude –University of Washington, PhD. chemical oceanography Reasons why I am teaching this course: –As a chemical oceanographer, I use chemistry every day. I want to teach chemistry so that students understand why it might be useful to them, and realize that first year chemistry can be interesting and fun. –What I want to get out of this course: for students to: understand chemical concepts + principles to provide real examples from marine science when possible. to develop students' problem-solving and critical thinking skills Major: Marine Science and Chemistry Hobbies: kayaking, telemark skiing, bicycling, swimming, dancing, community activism. I am very good at: contra dancing / skiing

How old are you? Calculate your age in seconds…

Learning outcomes for Chapter 1 Be able to distinguish between homogenous and heterogeneous mixtures, element and compounds Know how to convert between different units using dimensional analysis (aka factor label method) Be competent handling numbers using scientific notation with the appropriate number of significant figures

A mixture is a combination of two or more substances in which the substances retain their distinct identities. 1. Homogenous mixture – composition of the mixture is the same throughout. 2. Heterogeneous mixture – composition is not uniform throughout. brass (alloy), milk, solder cement, iron filings in sand Physical means can be used to separate a mixture into its pure components Examples??

An element is a substance that cannot be separated into simpler substances by chemical means. 114 elements have been identified 82 elements occur naturally on Earth gold, aluminum, lead, oxygen, carbon 32 elements have been created by scientists technetium, americium, seaborgium

A compound is a substance composed of atoms of two or more elements chemically united in fixed proportions. Compounds can only be separated into their pure components (elements) by chemical means. Water (H 2 O)Glucose (C 6 H 12 O 6 ) Ammonia (NH 3 )

? Seawater ? Is seawater a: 1.heterogenous mixture? 2.homogenous mixture? 3.Compound? 4.Element?

Classifications of Matter

A physical property can be measured and observed w/o changing the composition or identity of a substance. A chemical property: in order to observe this property, we must carry out a chemical change and alter the composition of the substance(s). Color, boiling point Length, weight burning paper; boiling and egg Physical or Chemical Property?

An extensive property of a material depends upon how much matter is is being considered. An intensive property of a material does not depend upon how much matter is is being considered. mass length volume density temperature color Extensive and Intensive Properties

International System of Units (SI)

Powers of ten pticsu/powersof10http://micro.magnet.fsu. pticsu/powersof10

Density – SI derived unit for density is kg/m 3 1 g/cm 3 = 1 g/mL = 1000 kg/m 3 density = mass volume d = m V A piece of platinum metal with a density of 21.5 g/cm 3 has a volume of 4.49 cm 3. What is its mass? d = m V m = d x V Is density an 1) intensive or 2) extensive property? Intensive, since it does not depend on mass 96.5g

Dimensional Analysis Method of Solving Problems 1.Determine which unit conversion factor(s) are needed 2.Carry units through calculation 3.If all units cancel except for the desired unit(s), then the problem was solved correctly. given quantity x conversion factor = desired quantity given unit x = desired unit desired unit given unit

Dimensional Analysis Method of Solving Problems Conversion Unit 1 L = 1000 mL How many mL are in 1.63 L? 1) L 2 /ml 2)1630 mL 3)1.630 mL 4) mL

The speed of sound in air is about 343 m/s. What is this speed in miles per hour? 1 mi = 1609 m1 min = 60 s1 hour = 60 min 343 m s = 767 mi hour meters to miles seconds to hours conversion units 1)5.92 x 10-5 mi/hr 2)153 mi/hr 3)767 mi/hr 4)1.99 x 106 mi/hr

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K = 0 C F = x 0 C K = 0 0 C 373 K = C 32 0 F = 0 0 C F = C

In Canada, my body temperature was 37°F. Did I have a fever?? Convert 37 0 C to degrees Farenheit. 0 F = x 0 C )yes, you had a fever! 2)No, your body temp was too cold 3)Just right… 98.6°F

Chemistry In Action On 9/23/99, $125,000,000 Mars Climate Orbiter entered Mar’s atmosphere 100 km (62 miles) lower than planned and was destroyed by heat. 1 lb = 1 N 1 lb = 4.45 N “This is going to be the cautionary tale that will be embedded into introduction to the metric system in elementary school, high school, and college science courses till the end of time.”

Scientific Notation I weigh 158 pounds = 1.58 x 10 2 lbs Number of atoms in 12 g of carbon: 602,200,000,000,000,000,000, x The mass of a single carbon atom in grams: )6.022 x )6.022 x )6.022 x )6.022 x 10 24

Counting Significant Figures All non zero digits are significant Zeros between non-zero digits are significant Zeros beyond the decimal point at the end of a number are significant. Zeros preceding the first non-zero digit in a number are not significant. Rounding off: When the first digit after those you want to retain is 4 or less, that digit and all others to its right are dropped. That last digit retained is not changed. When the first digit after those you want to retain is 5 or greater, that digit and all others to the right are dropped and the last digit retained is increased by one.

How many significant figures are in each of the following measurements? 24 mL2 significant figures 3001 g 4 significant figures m 3 3 significant figures 6.4 x 10 4 molecules 2 significant figures 560 kg2 significant figures 1.8

Significant Figures Addition or Subtraction The answer cannot have more digits to the right of the decimal point than any of the original numbers

Significant Figures Multiplication or Division The number of significant figures in the result is set by the original number that has the smallest number of significant figures 4.51 x = ÷ =

Significant Figures 1.8 Exact Numbers Numbers from definitions or numbers of objects are considered to have an infinite number of significant figures The average of three measured lengths; 6.64, 6.68 and 6.70? = = 6.67 Because 3 is an exact number = 7

Accuracy – how close a measurement is to the true value Precision – how close a set of measurements are to each other accurate & precise but not accurate & not precise 1.8

Accuracy – how close a measurement is to the true value Precision – how close a set of measurements are to each other accurate & precise but not accurate & not precise 1.8