Welcome to Chemistry 1:

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• Welcome to Chemistry 1
• A college preparatory course.

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• Cellphone NO!!!!
• Tuesday-Friday (A and B weeks)
• AUP
• Shoes in Locker
• Safety Contract
• Need to Buy
• Scientific Calculator
• Notebook or Binder

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• What do chemists study/do?
• What professions/college majors require a
  chemistry course?
• Where is chemistry important in
  business/industry?
• What household products are chemicals?
• Where in history was chemistry important?

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• Bronze Age (3300 1200 BC)
• Bronze Copper and tin
• Developed by Ancient Persians for weapons
• Egyptians (3000 B.C.)
• -Dying cloth
• -Embalming

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• Iron Age (1200 BC to ?)
• Iron used because tin becoming scarce
• Steel Iron mixed with carbon (VERY strong)
• Greeks (400 B.C.)
• -Elements (Earth, wind, fire,water)
• -Democritus Atomos

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History of Chemistry
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• Chinese (800 AD) Gunpowder, fireworks
• Middle Ages (500-1600 A.D.)
• -Alchemy turning base metals into gold

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History of Chemistry

• Industrial Age (1700 A.D.)
• Accurate Scales
• John Dalton (1803) Atomic Theory
• Frederic Wohler -organic synthesis, invents
  modern pharmacy

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• D. 1900-2009
• Electron
• Proton
• Nucleus/Bohr Model
• Neutron
• Quantum Mechanics
• Quarks
• Are we now in the Silicon age?

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Scientific Method

• A. Hypothesis
• untested, educated guess
• B. Theory successfully tested hypothesis
• C. Law Theory with NO known exceptions

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Scientific Method
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Scientific Method

• Hypotheses (climate change, competition,
  volcanoes, asteroid)
• Theory Asteroid (65 million years ago, iridium)
• Law - ?

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Science changes!!!!!
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Measuring

• Estimated place every measurement must have ONE
  estimated place.
• One place past the smallest marking

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Measuring
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Measuring
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Measuring
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Measuring
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Measuring
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Graphing

• 1. Label x and y axis including units
• 2. Mark Axis using a convenient scale
• 3. Title your graph The Dependence of Y on X
• 4. Mark dots with a small circle
• 5. Draw Best Fit line or curve

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Graphing

• Best Fit Line
• a. Used ONLY for linear relationships.
• b. Fits y mx b
• m slope
• b y-intercept
• c. If graph is almost perfect line, same dots
  above and below

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Graphing

• Best Fit Curve
• a. Used if points are clearly not linear.
• b. Can be fit to higher order eqns
• y mx2 b

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Graphing

• Rectangle A L X W
• Triangle A ½ B X H
• Circle A ?r2
• Irregular Shape?

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Graphing Lab

• Use centimeters
• TWO decimal places, last one is the estimated
  place
• Write down the letter of your shape
• See me for the actual value

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Scientific Notation

• 1. Powers of 10
• 100 1
• 101 10
• 102 10 X 10 100
• 103 10 X 10 X 10 1000

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Scientific Notation

• 2. The Andromeda Galaxy has 200,000,000,000
  stars
• 2 X 100,000,000,000
• 2 X 1011 stars

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Scientific Notation

• 3. A Helium atom masses
• 0.000,000,000,000,000,000,000,006,645g
• 6.645 X 10-24 g

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Scientific Notation

• 4. Who created Sci. Notation?
• a. Descartes in 1637 (I think, therefore I
  am)
• b. Became widely used in the 1800s by
  astronomers

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Scientific Notation

• 340
• 378,400
• 0.00234
• 0.000 000 000 0918
• 5.6 X 105
• 6.12 X 10-3
• 2.6 X 10-7
• 4 x 102

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Scientific Notation

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• 575,400
• 0.000723
• 0.000 000 0014
• 6.5 X 10-5
• 2.16 X 103
• 6.2 X 107
• 8 x 10-2

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Scientific Notation

• There are 900 students at Dallas
• 9 X 102
• 90 X 101
• 0.9 X 103

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Scientific Notation

• Write 4500 in scientific notation with the
  following exponents
• X 103
• X 102
• X 105
• X 104

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Scientific Notation

• Write 4500 in scientific notation with the
  following exponents
• 4.5 X 103
• 45 X 102
• 0.045 X 105
• 0.45 X 104

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Scientific Notation

• Examples
• (2.0 x 102) (3.0 x 103) 3.2 X 103
• (6.0 X 103) (3.0 x 10-5)2.0X108
• (2.0 x 107) - (6.3 x 105) 1.9X107

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Scientific Notation

• (4.0 x 105) x (3.0 x 10-1)
• (6.0 x 108) (3.0 x 105)
• (8.4x 1012) (8.4 x 109)
• NOTE 103 1 X 103

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Scientific Notation

• (4.0 x 105) x (3.0 x 10-1)1.2 X105
• (6.0 x 108) (3.0 x 105) 2 X 103
• (8.4x 1012) (8.4 x 109) 1 X 103
• NOTE 103 1 X 103

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Accuracy and Precision

• Accuracy how close the average of a set of
  measurements is to the accepted value (AAA)
• Precision How close a set of measured values
  are to one another (reproducibility)
• Always compare to a textbook value

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X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
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Accuracy and Precision

• Students did trials to measure the density of a
  metal. The accepted density is 7.2 g/cm3. Were
  they accurate or precise?
• Set 1 7.21 7.25 7.18
• Set 2 6.40 7.90 7.30
• Set 3 6.45 6.52 6.48

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Percent Error

• Percent Error Measure of accuracy
• Error Experimental Accepted X 100
• Accepted
• NOTE Experimental average of all trials

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• A student measures the density of a sample of
  copper at 8.75 g/mL. The accepted value is 8.96
  g/mL. Calculate the percent error.

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Error Analysis Range

• Range - Measure of precision
• Range highest trial lowest trial

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Error Analysis Range

• Example 1
• A student measures the density of a sample of
  lead and does four trials (11.3, 10.5, 11.9, 10.8
  g/cm3). Calculate the range and comment on
  precision.

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Significant Figures

• 1. Def - All of the measured values plus one
  estimated place
• 2. Ruler example (6.55 cm)
• 3. Indicator of the quality of a measurement
• GPA 3.872 vs 3.870
• Grades 95 vs 95.4

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Numbers with a Decimal

• 1. Always include a decimal if you can
• 2. All whole numbers plus any zeroes to the right
  Dot right

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• How many sig figs? Also, write in sci. notation
• 3.44 cm
• 60.001 cm
• 430.0 cm
• 0.0032 cm
• 0.00320 cm

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Numbers without a Decimal

• 1. Often poor measurements
• 2. Examples Not left
• 18,500 kg 120 ft

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Numbers without a Decimal

• How many sig figs? Also, write in scientific
  notation
• 10,500 cm
• 240 cm
• 120,000 cm
• 4 cm
• 45 cm

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Significant Figures

• How many significant figures are in the
  following? Also, write the numbers in proper
  scientific notation.
• 1508 cm 20.003 lb
• 300 ft 300.0 ft
• 0.00705 m 0.007050 m
• 1250 1250.
• 1250.0

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Significant Figures

• Round the following to three sig figs
• 32.45
• 32.449
• 0.0067530
• 0.003904
• 11,980

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How many significant figures? 0.00200 0.0020 1
00. 7450 144.0 200 8.40 X 1010 9.000 X
10-5 Round to three significant
figures 54.649999 1.456 X 10-4 300.847 8.605
X 107 200.49 0.00056732 0.0045282
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Significant Figures and Math

• 1. Math answers are only as good as the worst
  measurement.
• 2. Example
• Determining the area of a room
• 6.9 m by 10.478 m
• 3. Round AFTER you do the math.

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Significant Figures and Math

• Addition/Subtraction Rule - Keep the least number
  of decimal places.
• Examples
• 7.56 0.0327
• 0.375 0.00068
• 14.2203

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Significant Figures and Math

• Multiplication/Division Rule Answer contains
  the least of TOTAL significant figures
• Examples
• 23.4 X 32.25

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Significant Figures and Math

• 11.688 ? 4.0
• 7 X 7
• 4.68 X 1016 ? 9.1 X 10-5

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Significant Figures and Math

• 1. Multiple Operations Round when you change
  between add/sub and mult/div
• 2. Examples
• (0.56 X 11.73) 22.34
• (6.5688) 22.34
• (6.6) 22.34 28.9
• (12.45 11.643) X 2.68

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Significant Figures and Math

• 160 X 3.445
• 19.64 0.466
• 4.856 X 1010?2.0 X 102
• (16.44 ? 2.33) 22.3

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Warm-Up

• 19.64 - 14.465
• 320 X 0.04550
• 3.1415 X 1011 X 8.47 X 10-7
• (12.7 X 10.43) 23.8
• 0.00320 X 10-4 (write in proper sci. not.)

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Absolute Numbers

• 1. Also called exact numbers
• 2. Have an infinite numbers of significant
  figures
• 3. Counting numbers and values in definitions.
• 4. Examples
• 24 students Diameter 2r
• 1 km1000m
• 5. NEVER use exact numbers for determining sf.

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• Which of the following have or contain absolute
  numbers?
• Y X3 50 people
• 1 km 1000 meters 37 apples
• 2.85 grams 400 apples
• 1 cm 10 mm

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Absolute Numbers

• If we divide 1.66 lbs of candy among 3 people,
  how much candy will each person get?
• (Ans 0.553 lbs/person)
• What is the diameter of a circle whose radius is
  3.835 m?
• (Ans 7.670 m)

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• What is the diameter of a circle with a radius of
  2.567 cm?
• If we buy 1.84 pounds of coffee and divide it
  among three people, how much coffee will each
  person get?
• How many centimeters is 7.565 meters?
• How would you divide 12.35 kg of candy among
  eight children?

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Metric

• Qualitative data with no number
• Quantitative data with a number

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Metric

• SI System Le System International dUnites
• 1670 Gabriel Mouton (French Vicar)
• 1795 Adopted by France

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Metric
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Metric

• 4. Base ten scale
• 1000 m 1 km
• 100 m 1 hm
• 10 m 1 dam
• 1 m 1 m
• 1 m 10 dm
• 1 m 100 cm
• 1 m 1000 mm

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Metric

• Standard Units
• Length meter
• Mass kilograms
• Time second

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Metric

• Common Units
• Length meter
• Volume liter
• Mass grams
• Time second
• Energy Joules

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Metric

• Factor Label method
• 55 cm ? m
• 0.055 L ? mL
• 0.00456 km ? cm
• 550 cm2 ? m2
• 25 miles/hr ? m/s

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Metric

• 129 hrs ? Days
• 0.468 m?km
• 825 cm2 ? in2
• 0.0023 L ? mL
• 0.468 m ? mm
• 1245 cm ? km
• 55 mi/hr ? km/hr
• 55 mi/hr ? m/min

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Metric

• 129 hrs ? Days 5.38 days
• 0.468 m?km 0.000468
• 825 cm2 ? in2 128 in2
• 0.0023 L ? mL 2.3 mL
• 0.468 m ? mm 468 mm
• 1245 cm ? km 0.01245 km
• 55 mi/hr ? km/hr 89 km/hr
• 55 mi/hr ? m/min 1500 m/min

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Temperature
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Temperature

• Absolute Zero
• All atomic and molecular motion stops
• Coldest possible temperature
• Never reached absolute zero
• Liquid Nitrogen 77 K (-196 oC)
• Dry Ice 216 K (-56.6 oC)

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Temperature

• Conversion Formulas
• F 1.8 (oC) 32
• K C 273
• C K 273

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Temperature

• Ex 24 oC ? oF
• 48oF ? oC
• 177 K ?oC

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Temperature

• 102 oF ? oC
• -10.0 oC ? oF
• 25 oC ? K
• 177 K ? oF
• 310 oF ? K

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Temperature

• 102 oF ? 39oC
• -10.0 oC ? 14 oF
• 25 oC ? 298 K
• 177 K ? -141 oF
• 310 oF ? 427 K

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Temperature

• 25 oC ? oF
• 50 oF ? K
• 310 K ? oC
• 10 K ? oC
• -15 oC ? K

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Temperature

• 25 oC ? 77 oF
• 50 oF ? 283 K(10 oC)
• 310 K ? 37 oC
• 10 K ? -263 oC
• -15 oC ? 258 K

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Dont let it be you!!!!
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• Page 39
• a) 0.77 b) 13.0 c) 32 d) 326
• a) 5000 m b) 1400 ft2 c) 1.21 in2
• d) 100 yd
• 23 a) 7 b) 12.7 c) 1.49

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• Page 40 (40-42, 53, 55, 57, 60)
• a) 6.8 X 106 6800 6.8
• b) 786 0.786 7.68X10-4
• c) 4452 4.452 4.452 X 10-3
• 384,300km 55) 0.376 qt
• 57) 114 g 60) 109 yd (10.9 yd)

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• a) 7
• b) 12.7
• c) 1.49
• a) 6.8 X 106 6800 6.8
• b) 786 0.786 7.68X10-4
• c) 4452 4.452 4.452 X 10-3

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• How many significant figures in 1508?
• How many significant figures in 200.0?
• How many significant figures in 0.00705?
• What are the two components of bronze?
• What are the two components of steel?
• Define precision
• Define accuracy

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• Warm Up (Write in notebook)
• UFOs hypothesis, theory or law?
• How about ghosts?
• The Big Bang?

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• a4 b3 c2 d4 e3 f6 g2 h3
• 2a) 20.
• b) 960
• c) 55.2
• d) 5800
• e) 6.27
• f) 417
• g) 2.7

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• B2) 3ft1yd,
• 10 dm 1 m
• 1.00 gal 3.78 L
• 2.20 lb 1.00 kg
• B3) 15.5 miles
• B4) 2.16, 9.72 oz
• B5) 366 cm
• B6) 8.94