Important Things to Note
1. Tardiness is considered an absence.
2. You are given 4 free absences before deductions start accruing. Attend class ALL the time.
3. 2 In-class Exams (one of which is the midterm) 25%
4. 1 Lab Exam close to the end of the semester (5%)
5. 1 COMPREHENSIVE Final Exam (25%)
6. 12 Quizzes ( 6 before midterms and 6 after) (25%) – lowest 2 quizzes per term are dropped (total of 4)
7. No make-ups on quizzes because of the drop rule.
8. You fail the lab portion, you fail the course.
9. Bring a scientific calculator to class EVERYDAY!
10.Engage/participate in class. You take out what you put in it.
11.Do NOT CHEAT on quizzes, exams, labs etc…
12. Treat everyone with respect!
13. I teach FAST. Keep up and study!
14.If you get offended easily, please take the class with a different teacher.
15.My class, my rules. I run it the way I see fit. Do not battle with me or give me attitude!
NOTE For Lab
• We MEET first in IC 419 for the pre-lab quiz and pre-lab instructions before performing the lab in IC 416.
• Bring lab notebook, lab manual, data sheet(s), calculator, apron and lab goggles.
Important Dates (Sections A and B)
• Exam 1 - Tuesday, September 26
• Exam 2 - Tuesday, November 7
• Lab Exam – Tuesday, November 14
• Final Exam – Monday, December 4 @ 10:15 a.m. – 12:15 p.m. in IC 111
Important Dates (Sections C and D)
• Exam 1 - Thursday, September 28
• Exam 2 - Thursday, November 9
• Lab Exam – Thursday, November 16
• Final Exam – Tuesday, December 5 @ 8:00 a.m. – 10:00 a.m. in IC 111
Topics
• Introduction• Scientific Method• Classifications of Matter• Properties of Matter• Units of Measurement – Metric system• Temperature Conversion• Metric Conversion (Prefixes)• Accuracy vs. Precision• Significant Figures• Density
Definitions
• Elements – can’t be decomposed further into simpler substances
- 118 elements presently - Lv (element 116 -
livermorium)• - Fl (element 114 - flerovium)• Compound – combination of 2 or more
elements• Pure substance – has distinct properties and
composition; does not vary from sample to sample (ex. Water, NaCl)
Definitions
• Mixtures – combinations of 2 or more substances (ex. sugar in water)
• 2 Types of Mixtures
• 1. Homogenous Mixtures (solutions) = 1 phase
• 2. Heterogeneous Mixtures = > 2 phases
Solution
• Solution – homogenous mixture
• A solution is not necessarily a liquid. Can be gas or solid.
Physical vs. Chemical Properties
• Physical properties – can be measured w/o changing identity and composition of substance (ex. Boiling pt.,freezing pt., color, odor, density, hardness)
• Chemical properties – describe how substance reacts or changes to form other compounds (ex. Flammability, toxicity)
Changes of State and Properties
• Physical changes – does not change composition of compound
• Chemical changes – converts to a different chemical substance
• Intensive Properties – independent of amt. (ex. Density, Temperature, Melting Pt)
• Extensive Properties – dependent on amt. (ex. Mass, Volume)
Units of Measurement
• Mass – grams; kilogram• Length – centimeter; meter• Volume – milliliter or cubic
centimeter (cm3)• Temperature – Celcius;
Kelvin
Precision vs Accuracy
• Accuracy – when acquired value agrees with true value
• Precision – when acquired values exhibit reproducibility
Significant Figures
• More significant figures = more certainty
• Helps in determining how to round measured values and still precise
SIGNIFICANT FIGURES
• In counting and definitions, there are an infinite number of sig figs
• In measurements, the number of sig figs consists of all certain and the first uncertain digits
• Unit conversions do not determine # of sig. figs.
Rules of Significant Figures
• 1. Non-zero integers always count.
• Ex. 1234.5 grams = 5 Sig. Figs.
• 2. Captive zeros are always significant.
• Ex. 100.3 grams = 4 Sig. Figs.
Rules of Significant Figures
• 3. Leading zeros are NEVER significant.
• Ex. 0.6780 grams = 4 Sig. Figs.
• 4. Trailing zeroes are significant ONLY if there is a decimal point
• Ex. 12.0 grams = 3 Sig. Figs• 120 grams = 2 Sig. Figs
Rules of Significant Figures
• 5. Exact numbers (obtained by counting) are infinite and do not determine the number of significant figures.
• Example: 4 cows = ?
Rules of Significant Figures
• Multiplication/Division
–Answer will have the same # of sig figs as the value with the least # of sig figs• Ex: 3.8 x 200.0 = 2 Sig. Figs.
Rules of Significant Figures
• Addition/Subtraction
• Answer has the same # of decimal places as the number with the least # of decimal places
• Ex. 3.1 + 2.500 + 5.76 = 11.4
Rounding
• Look only to the right of the number you are rounding to:
• - If 5 or more, round up
• - If less than 5, round down
General Rule
• Carry ALL figures through to the end of a problem while keeping track of significant figures along the way. Round the final answer to the correct number of significant figures
Problem
• Indicate the number of sig. figs. in each of the following measured quantities:
• A. 358 kg
• B. 0.054 s
• C. 6.3050 cm
• D. 0.0105 L
• E. 7.0500 x 10-3 m3
Problem
• Round each of the following numbers to 4 sig. figs. And express the result in standard exponential or scientific notation.
• A. 102. 53070• B. 656, 980• C. 0.008543210• D. 0.000257870• E. - 0. 0357202
Problem
• Carry out the following operations and express the answer with the appropriate number of sig. figs.
• A. 12.0550 + 9.05
• B. 257.2 – 19.789
• C. (6.21 x 103)(1.1050)
• D. 0.0577 / 0.753
Prefixes in Metric System
• Mega - million• Kilo - 1,000• Hecto - 100• Deka - 10• ----- - 1 (liter, gram, meter)• Deci - 1/10 or 0.1• Centi - 1/100 or 0.01• Milli - 1/1000 or 0.001
Trick to Unit Conversions
• Arrange the values with units such that you can cancel what you do not want.
• You should only end up with the desired unit.
Density
• Is the amount of mass in a unit volume of the substance
• Is affected by Temperature. – The higher the temp., the lower the density.
D = mass of substance = grams volume of substance mL or cm3
Different ways of calculating volume
• I. For solids with regular shapes:
• A. For a cube: Vcube = s3
• B. For a rectangular solid, V = L x W x H
• C. For a cylinder: V= r2h
• D. For a sphere: V = 4/3 r3
Different ways of calculating volume
• III. For a liquid
• Use of graduated cylinder, beaker, pipet or buret.
Problem
• A cube of osmium metal 1.500 cm on a side has a mass of 76.31 grams at 25 oC. What is its density in g/cm3 at this temperature?
Problem
• The density of titanium metal is 4.51 g/cm3 at 25 oC. What mass of titanium displaces 65.8 mL of water at 25 oC?
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