IB/Accelerated Chemistry
Larry J. Scheffler
Lincoln High School
1600 SW Salmon
Portland, OR 97205
IB/Accelerated Chemistry
Instructor : Mr. Larry J. Scheffler
Email : lscheffl@pps.k12.or.us
Web: http://lincoln.pps.k12.or.us/lscheffler/
Copy this web address and set a bookmark on
your web browser. You will be using this site all
year
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Class Information Form
Your Name
Code name
(use something that you will remember, I will
post grades under that name)
Address
Telephone Number
Email
School ID Number
Year in School
Check previous math and science classes
Check computer experience and skills
Answer the four questions that follow
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IB Chemistry 1-2 Agenda
Periods 1 , 3, and 5
• Information forms
• Brief overview of the course
• Access to information on the internet
• Class Policies
• Safety contracts
• Chemical Hazards
• Scientific Methods
• Assignments
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IB Chemistry 1-2 Assignments
• Tomorrow: Read the Lab Density
Determination
• Begin reading through
• Next week: Read chapter 1 in textbook
• Tuesday Sept 15: Return signed the PPS
Safety Agreement and read thoroughly the
chemical hazards handout
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Introduction to Chemistry
Chemistry
The study of matter and its relationships
The study of materials and how they
interact
The Central Science
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Chemistry Topics Include
Atomic Theory
Periodic Table
Bonding
Formulas and
Stoichiometry
States of matter
Calorimetry /
Thermodynamics
Solutions
Kinetics
Equilibrium
Acids and Bases
Oxidation
Reduction
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Is Chemistry Hard??
Maybe! --- but you will
develop skills that are
valuable for the rest of
your life!
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Is Chemistry Hard??
Well maybe but you will develop skills
that are valuable for the rest of your life
These include:
Abstract Thinking
Critical Thinking
Analysis
Logic
Math Skills
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Is Chemistry Hard??
Well maybe but you will develop skills
that are valuable for the rest of your life
These include:
Abstract Thinking
Critical Thinking
Analysis
Logic
Math Skills
Problem Solving
Communication
Time Management
Hazards Management
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Chemical Hazards
Hazard Criteria
A Threshhold Limit value of less than 500 ppm
A Lethal dose (LD50) less than 500mg per kg
Readily polymerizable
Flashpoint less than 140oF
A strong oxidizer or reducing agent
Highly corrosive
Carcinogen, mutagen,or teratogen
Radioactive
See the handout for more definitions and criteria for
chemical hazards
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Scientific Methods
• Always based on observation and
experimentation
• Observable and reproducible evidence
are required to support conclusions
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Scientific Method
Investigation process
- Preliminary observations
-
Formulation of a hypothesis
Design experiments to test the hypothesis
Evaluate and interpret data
Draw appropriate conclusions
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Scientific Methods
The scientific method is not necessarily
a chronological order that scientists
always follow.
But remember ………..
Scientific information is always based
on evidence. The emphasis is always
on information that we can gain from
observations and experiments
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Hypothesis, Theory and Law
A Hypothesis is a tentative explanation or
expected result based on past evidence
and experience
A Theory is an explanation of a phenomona
based on the results of scientific
experimentation.
A Law is a principle that can be observed
repeatedly in the world over a long period
of time
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Matter
• Has both volume and mass
• Exists in various states:




Solid
Liquid
Gas
Plasma
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Forms of Matter
• Element
• Compound
• Mixture
 Homogeneous
 Heterogeneous
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Elemental Composition
of the Earth
Properties of Matter
• Physical -
• Chemical • Extensive • Intensive -
Color
Density
Melting point
How the substance reacts with
other substances
Depend on the amount of
material
Independent of the amount of
material
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Density
• Definition
Ratio of mass to volume
• Formula
D = Mass/ volume
Density is an intensive property. It
is constant for most solids and
liquids, but it depends on the
pressure and temperature for a
gas
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Physical and Chemical Changes
• Physical -
• Chemical -
A change in state or shape.
Affects the physical properties
but retains the properties of the
substance
Undergoes a chemical reaction.
A new substance is formed with
new physical and chemical
properties
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Problem Solving Density
Formulas
Density = Mass/volume
D = m/V
M = DV
V = m/D
If you solve the formula
correctly the units will
match
D = m/V = g/cm3
M = DV = (g/cm3) /(cm3) = g
V = m/D =(g)/(g/cm3) = cm3
Units
Density = g/cm3
Mass = grams or g
Volume = cubic centimeters or
cm3
Temperature Scales
Kelvin Celsius Fahrenheit
Boiling point
of water.
373 K
100 oC
212 oF
Freezing point
of water.
273 K
100 oC
32 oF
0K
-273 oC
-460 oF
Absolute Zero.
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Temperature Conversions
Fahrenheit to Celsius
oC
= 5/9 ( oF - 32)
Celsius to Fahrenheit
o
F = 9/5 oC + 32
Celsius to Kelvin
K = oC +273
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Measurement
Measurements in the laboratory will
normally be made using the metric
system and SI units where feasible
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Measurement Issues
Uncertainty
Accuracy
Precision
Error
Significant Figures
Scientific Notation
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Uncertainty in Measurements
• All measurements are limited by the
instruments used to make them
• The uncertainty of a measurement
depends on the quality with which a
measurement is made
• The uncertainty depends on the
precision and accuracy of the
measurement
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Accuracy and Precision
• Accuracy is the degree of closeness of a
measured or calculated quantity to its actual (true)
value.
• Precision is also called reproducibility or
repeatability. It is the degree to which further
measurements or calculations show the same or
similar results.
In other words
• Accuracy refers to the proximity of a
measurement to the true value of a quantity.
• Precision refers to the proximity of several
measurements to each other.
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Accuracy and Precision
A measurement may be
either accurate or
precise, both or neither.
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Significant Figures
A measurement is always limited by the precision of the
Instrument. An understanding of significant figures is
important to express the appropriate precision of a
measurement
• Only zeros can be non-significant digits
• There are two cases where a zero may be non
significant:
1. Zeros at the end of numbers greater
than 1 that do not refer to a precise count
2. Zeros in front of the first non zero
digit in
numbers less than 1
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Significant Figures
• 0.004070 -- The zeros shown in red are not
significant. The number is precise to 4 significant
digits
• With numbers having a zero at the end the number of
significant figures depends on the precision with which
the number is known.
• 40000 -- one significant digit. The number is known
to the nearest ten thousand.
• 40000 -- three significant digits. The number is
known to the nearest hundred.
• 40000 -- five significant digits. The number is known
to the nearest unit.
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Scientific Notation
• Large numbers are hard to visualize.
Scientific notation writes numbers in two
parts: a number between 1 and 10 and
a power of 10
• Examples
• 3.00 x 108 rather than 30 000 000
• 4.82 x 10-5 rather than 0.0000482
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Error
• The error in a measurement refers to the degree of
fluctuation in a measurement. It is usually expressed
as a + value
• Example: a measurement of a mass from the scale
could be recorded as 21.40 g + 0.01 g.
• It is often helpful to record measurements as relative
error or percent error
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