Welcome to AP Chemistry

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Welcome to AP Chemistry
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What is AP Chemistry?

• It is several things
• Equivalent of 1 year college inorganic chemistry
  class
• A class that will prepare you for a test
• May 17
• Hard work
• A wonderful way to start the day
• Now on to the details

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Rules and Procedures

• You know the basic rules but here are a few that
  are specific for this class
• No food drink or gum
• LATE WORK
• If you forget to bring in your homework, I will
  accept it ONE day late with a parent's signature,
  for full credit.
• I will not accepted it any later.

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Rules and Procedures

• MAKE-UP WORK
• It is your responsibility to make up all the work
  you missed. You have the same number of days
  that you were absent to turn in the missing
  work.
• Pick up any missing work, and notes before or
  after class.
• If you miss a test or quiz, it must be made up
  outside class.

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Rules and Procedures

• TARDIES
• You will be allowed one free" tardy per
  semester.
• The second and every subsequent tardy will result
  in a detention.
• Repeated tardies will result in parent contacts,
  and referrals, AND MAY RESULT IN BEING DROPPED
  FROM THE CLASS.

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Rules and Procedures

• PASSES
• Since every minute of class time is valuable,
  hall passes will be given only on an emergency
  basis, with a limit of one per semester, except
  under special circumstances.

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Rules and Procedures

• LAB- Because of the importance of safety in the
  lab, violation of laboratory safety rules and
  procedures may result in loss of lab privileges.

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Grading

• Percentage scale
• 94-100 A 70-75 C
• 90-94 A- 65-70 C-
• 87-90 B 62-65 D
• 84-87 B 58-62 D
• 80-84 B- 55-58 D-
• 75-80 C 0-54 F

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Grading

• Quarter Grade
• Tests 50
• Homework/Classwork 20
• Quizzes 15
• Lab Reports 15
• Semester Grade
• 40 from each quarter
• 20 on final

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Extra Credit!!

• Assignments will be provided approximately mid-
  quarter.
• They may be turned in any time until the due
  date,(during the last week of the quarter)
• Extra credit may be used to raise the quarter
  grade by up to one letter grade.
• Extra credit is meant to be extra, so it will not
  be accepted if more than 10 of the other
  assignments are not turned in.

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What you need for class

• Paper
• Pencil or pen,
• Calculator- scientific
• Book?
• Not unless I let you know
• Lab Notebook

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Internet Ready

• http//mrgreen.tierranet.com
• My email is tvgreen_at_aol.com

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Why First Period?

• College chemistry labs take more than 56 minutes,
• To do those labs we will have to come early
• I will give you notice of when

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Any questions?

• Lets get started

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Significant figures

• Meaningful digits in a MEASUREMENT
• Exact numbers are counted, have unlimited
  significant figures
• If it is measured or estimated, it has sig figs.
• If not it is exact.
• All numbers except zero are significant.
• Some zeros are, some arent

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Which zeroes count?

• In between other sig figs does
• Before the first number doesnt
• After the last number counts iff
• it is after the decimal point
• the decimal point is written in
• 3200 2 sig figs
• 3200. 4 sig figs

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Doing the math

• Multiplication and division, same number of sig
  figs in answer as the least in the problem
• Addition and subtraction, same number of decimal
  places in answer as least in problem.

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More Preliminaries

• Scientific Method
• Metric System
• Uncertainty

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Scientific method.

• A way of solving problems
• Observation- what is seen or measured
• Hypothesis- educated guess of why things behave
  the way they do. (possible explanation)
• Experiment- designed to test hypothesis
• leads to new observations,
• and the cycle goes on

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Scientific method.

• After many cycles, a broad, generalizable
  explanation is developed for why things behave
  the way they do
• Theory
• Also regular patterns of how things behave the
  same in different systems emerges
• Law
• Laws are summaries of observations

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Scientific method.

• Theories have predictive value.
• The true test of a theory is if it can predict
  new behaviors.
• If the prediction is wrong, the theory must be
  changed.
• Theory- why
• Law - how

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Observations
Hypothesis
Modify
Experiment
Prediction
Experiment
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Metric System

• Every measurement has two parts
• Number
• Scale (unit)
• SI system (le Systeme International) based on the
  metric system
• Prefix base unit
• Prefix tells you the power of 10 to multiply by -
  decimal system -easy conversions

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Metric System

• Base Units
• Mass - kilogram (kg)
• Length- meter (m)
• Time - second (s)
• Temperature- Kelvin (K)
• Electric current- ampere (amp, A)
• Amount of substance- mole (mol)

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Prefixes

• giga- G 1,000,000,000 109
• mega - M 1,000,000 106
• kilo - k 1,000 103
• deci- d 0.1 10-1
• centi- c 0.01 10-2
• milli- m 0.001 10-3
• micro- m 0.000001 10-6
• nano- n 0.000000001 10-9

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Deriving the Liter

• Liter is defined as the volume of 1 dm3
• gram is the mass of 1 cm3

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Mass and Weight

• Mass is measure of resistance to change in motion
  
• Weight is force of gravity.
• Sometimes used interchangeably
• Mass cant change, weight can

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Uncertainty

• Basis for significant figures
• All measurements are uncertain to some degree
• Precision- how repeatable
• Accuracy- how correct - closeness to true value.
• Random error - equal chance of being high or low-
  addressed by averaging measurements - expected

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Uncertainty

• Systematic error- same direction each time
• Want to avoid this
• Better precision implies better accuracy
• you can have precision without accuracy
• You cant have accuracy without precision

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Dimensional Analysis

• Using the units to solve problems

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Dimensional Analysis

• Use conversion factors to change the units
• Conversion factors 1
• 1 foot 12 inches (equivalence statement)
• 12 in 1 1 ft.
  
  1 ft. 12 in
• 2 conversion factors
• multiply by the one that will give you the
  correct units in your answer.

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Examples

• 11 yards 2 rod
• 40 rods 1 furlong
• 8 furlongs 1 mile
• The Kentucky Derby race is 1.25 miles. How long
  is the race in rods, furlongs, meters, and
  kilometers?
• A marathon race is 26 miles, 385 yards. What is
  this distance in rods, furlongs, meters, and
  kilometers?

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Examples

• Science fiction often uses nautical analogies to
  describe space travel. If the starship U.S.S.
  Enterprise is traveling at warp factor 1.71, what
  is its speed in knots?
• Warp 1.71 5.00 times the speed of light
• speed of light 3.00 x 108 m/s
• 1 knot 2000 yd/h exactly

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Examples

• Apothecaries (druggists) use the following set of
  measures in the English system
• 20 grains ap 1 scruple (exact)
• 3 scruples 1 dram ap (exact)
• 8 dram ap 1 oz. ap (exact)
• 1 dram ap 3.888 g
• 1 oz. ap ? oz. troy
• What is the mass of 1 scruple in grams?

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Examples

• The speed of light is 3.00 x 108 m/s. How far
  will a beam of light travel in 1.00 ns?

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Temperature and Density
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Temperature

• A measure of the average kinetic energy
• Different temperature scales, all are talking
  about the same height of mercury.
• Derive a equation for converting ºF toºC

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0ºC 32ºF
32ºF
0ºC
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100ºC 212ºF
0ºC 32ºF
0ºC
100ºC
212ºF
32ºF
40
100ºC 212ºF
0ºC 32ºF
100ºC 180ºF
0ºC
100ºC
212ºF
32ºF
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100ºC 212ºF
0ºC 32ºF
100ºC 180ºF
1ºC (180/100)ºF
1ºC 9/5ºF
0ºC
100ºC
212ºF
32ºF
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ºF
ºC
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(0,32) (C1,F1)
ºF
ºC
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(0,32) (C1,F1)
(120,212) (C2,F2)
ºF
ºC
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Density

• Ratio of mass to volume
• D m/V
• Useful for identifying a compound
• Useful for predicting weight
• An intrinsic property- does not depend on what
  the material is

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Density Problem

• An empty container weighs 121.3 g. Filled with
  carbon tetrachloride (density 1.53 g/cm3 ) the
  container weighs 283.2 g. What is the volume of
  the container?

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Density Problem

• A 55.0 gal drum weighs 75.0 lbs. when empty. What
  will the total mass be when filled with ethanol?
  density 0.789 g/cm3 1 gal 3.78 L
  1 lb 454 g