Welcome to
AP Chemistry
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
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.
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.
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.
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.
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.
Grading
• Percentage scale
94-100% A
90-94% A87-90% B+
84-87% B
80-84% B75-80% C+
70-75%
65-70%
62-65%
58-62%
55-58%
0-54%
C
CD+
D
DF
Grading
• Quarter Grade
– Tests 50%
– Homework/Classwork 20%
– Quizzes 15%
– Lab Reports 15%
• Semester Grade
– 40% from each quarter
– 20% on final
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.
What you need for class
•
•
•
•
Paper
Pencil or pen,
Calculator- scientific
Book?
– Not unless I let you know
• Lab Notebook
Internet Ready
• http://mrgreen.tierranet.com
• My email is tvgreen@aol.com
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
Any questions?
• Lets get started
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 aren’t
Which zeroes count?
•
•
•
•
•
•
In between other sig figs does
Before the first number doesn’t
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
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.
More Preliminaries
Scientific Method
Metric System
Uncertainty
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
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
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
Observations
Hypothesis
Theory
(Model)
Modify
Experiment
Prediction
Law
Experiment
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
Metric System
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•
•
•
•
•
•
Base Units
Mass - kilogram (kg)
Length- meter (m)
Time - second (s)
Temperature- Kelvin (K)
Electric current- ampere (amp, A)
Amount of substance- mole (mol)
• giga-
G
Prefixes
1,000,000,000 109
106
• mega - M
1,000,000
•
•
•
•
•
•
103
0.1
10-1
0.01
10-2
0.001
10-3
0.000001
10-6
0.000000001 10-9
kilo decicentimillimicronano-
k
d
c
m
m
n
1,000
Deriving the Liter
3
• Liter is defined as the volume of 1 dm
3
• gram is the mass of 1 cm
Mass and Weight
• Mass is measure of resistance to change
in motion
• Weight is force of gravity.
• Sometimes used interchangeably
• Mass can’t change, weight can
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
Uncertainty
• Systematic error- same direction each
time
• Want to avoid this
• Better precision implies better accuracy
• you can have precision without
accuracy
• You can’t have accuracy without
precision
Dimensional Analysis
Using the units to solve problems
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.
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?
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
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?
Examples
• The speed of light is 3.00 x 108 m/s. How
far will a beam of light travel in 1.00 ns?
Temperature and Density
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
0ºC = 32ºF
0ºC
32ºF
100ºC = 212ºF
0ºC = 32ºF
0ºC 100ºC
212ºF 32ºF
100ºC = 212ºF
0ºC = 32ºF
100ºC = 180ºF
0ºC 100ºC
212ºF 32ºF
100ºC = 212ºF
0ºC = 32ºF
100ºC = 180ºF
1ºC = (180/100)ºF
1ºC = 9/5ºF
0ºC 100ºC
212ºF 32ºF
ºF
ºC
(0,32)= (C1,F1)
ºF
ºC
(0,32) = (C1,F1)
(120,212) = (C2,F2)
ºF
ºC
Density
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•
•
•
•
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
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?
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
gal = 3.78 L
454 g
1
1 lb =