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
Base Units
 Mass - kilogram (kg)
 Length- meter (m)
 Time - second (s)
 Temperature- Kelvin (K)
 Electric current- ampere (amp, A)
 Amount of substance- mole (mol)

Prefixes

giga-

mega - M
kilo  deci centi milli micro nano
G
k
d
c
m
m
n
1,000,000,000 109
1,000,000
106
103
0.1
10-1
0.01
10-2
0.001
10-3
0.000001
10-6
0.000000001 10-9
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
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
1 gal = 3.78 L
1 lb = 454 g