Intro to Chemistry
Chapter 1, section 3 and Chapter 2, and 2 formulas from Chapter 3
A Preview of Coming Attractions
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RIGOROUS
ONLY INTENDED FOR MATURE STUDENTS!
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Graffiti Wall
S Graffiti wall
S Keep it clean and school appropriate.
S Write whatever you like on the orange
wall.
S Maybe it will end up being cool.
Taking
notes...
CUES
1-2
words
CUES
Main part for Notes
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. Use bullet points
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.
.
.. Abbreviate
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. Draw pictures to
. help you.
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. You do not have
. to write in
. complete
. sentences.
Main Part for Notes
化学
S Chemistry in Japanese
S Literally means “change study.”
S Chemistry is the study of matter: the
composition of matter and the changes
matter undergoes.
S Did you start taking notes yet?
Chemistry is not relevant to my
life. Am I ever going to use
THIS?
How should I know?
But since Chemistry is
all around you, I’m
going to guess YES.
Do you like to cook?
Do you want a pool?
The Scientific Method
Chapter 1.3
S Observation
S Use your senses to make observations and
suggest questions.
S Hypothesis
S A testable “educated guess.”
S Experiment
S Supports and proves your hypothesis (or doesn’t
support and disproves)
The Scientific Method
S Analysis of Data
S Analyze data collected during the experiment.
S Conclusion
S What happened?
S Was your hypothesis supported or not (try NOT to
think of it as success vs failure)?
S How could you improve your experiment?
S How could you expand upon your original
experiment?
Scientific Theory
S Theory
S A detailed explanation explaining why an experiment
works the way it does.
S A theory can never be PROVEN completely true.
S A theory can always be disproved if new data doesn’t
support the theory.
S If that happens, theory needs to be revised or
discarded.
Scientific Theory
S Theory
S It doesn’t matter how many scientists believe it.
Believing it is true doesn’t make it so.
S Consensus isn’t science. The only thing that matters is
if the scientific data supports the theory.
Scientific Law
S Law
S A law is a statement of fact, usually concerning a
natural phenomenon.
S It doesn’t explain how or why.
S Theories explain. Laws don’t explain. They just
tell you what it is.
S Lets talk about an important law:
The Law of
Conservation of Mass
S In any chemical reaction or physical change, matter can
neither be created nor destroyed.
S The amount of matter (mass) doesn’t change.
S However, the identity of the matter (what type of
substance it is) could change.
S mass of the reactancts = mass of the products
Chapter 2
S Back to matter…
S Matter can be broken down into substances
and mixtures.
S Substances are pure.
S Elements (smallest part of an element is an
atom)
S Compounds (smallest part of a compound is a
molecule)
Substances vs mixtures
S Carbon is a substance.
S Water is a substance.
S Air is a mixture of substances (O2, N2,
CO2, etc)
Substances vs mixtures?
S You try some
S Methane (natural gas)
S Coffee
S Copper
S Salt
S Dirt
S Sand
Substances: Elements
S Elements are on the Periodic Table.
S 118 elements exist
S 90 occur naturally (1-92 except for 43Tc
and 61Pm)
S Elements 93 and higher are man made
(most of them by Dr. Glenn Seaborg)
Substances: Compounds
S Compounds are pure substances too.
Common compounds are:
S
S
S
S
S
S
Salt (sodium chloride)
Sugar (sucrose)
Baking Soda (sodium bicarbonate)
Sand (silicon dioxide)
Rubbing Alcohol (isopropanol)
Carbon dioxide
Ionic Compounds vs
Molecular Compounds
S There are 2 types of compounds
S Ionic compounds have ionic bonds and are
composed of positive and negative ions.
S Ions are formed when atoms lose or gain
electrons.
S Molecular compounds have covalent bonds.
S Electrons are shared between atoms. There
are no ions or charges.
Substances: Elements and
Compounds
S How do you tell if it’s an element or a
compound?
S An element cannot be broken down into
anything simpler.
S A compound can be separated into smaller
elements. You must use a chemical reaction
to break down a compound.
Compound vs Mixture
S How do you tell if it’s an compound or a
mixture?
S A compound is bonded together. You must use a
chemical reaction to break down a compound
into elements.
S A mixture isn’t bonded together. The substances
are just mixed together. A mixture may be
separated by physical separation techniques.
What are physical separation
techniques?
S Evaporation—can separate DISSOLVED
solids from the liquid.
S Filtration—can separate UNDISSOLVED
solids from the liquid.
S Decanting—can separate a dense undissolved
solid from the liquid (because the solid is on
the bottom and so you can pour off the liquid).
A physical separation technique
sometimes tested on the SOL.
S Chromatography
S Can be used to separate a mixture of solids
dissolved in a liquid.
S Ink
S Natural dyes
Homework
S HW: research chromatography online. Type a 3 paragraph essay (5
for Adv Chem) on chromatography. MLA Format.
S Cite your sources (need 3, none of which may be Wikipedia;
however, Wikipedia is a great place to start and learn about the
topic).
S Schwartz Definition of Paragraph = 5 well constructed sentences
which all relate to the same main idea.
Chemical Reactions
S Reactants  Products
S You can have 1 or more reactants
S You will produce 1 or more products
S How many you need and how much you produce
is characteristic of the specific reaction.
S We will study 5 major types of reactions starting
in Chapter 8.
S Chemical reactions are PERMANENT and NOT
reversible.
Physical Properties
S Matter has both physical and chemical
properties.
S Physical properties can be observed without
CHANGING the type of matter.
S When solid water (ice) melts it becomes liquid
water. A change of state is a physical change (Δ or
delta means change).
S Physical changes are NOT permanent and are
reversible.
Chemical Properties
S Chemical properties can be ONLY be
observed BY CHANGING the type of
matter.
S When salt (NaCl) is dissolved in water, a
solution is formed. That is a physical change.
The salt is still salt and the water is still water.
You can separate them easily by evaporating
the water.
Chemical Properties
S But when sodium oxide (Na2O) is dissolved in
water a solution is formed at first, but then a
chemical reaction occurs. That is a chemical
change. Sodium oxide reacts with water to form
sodium hydroxide (NaOH). If you evaporate the
water, you will have solid NaOH not Na2O.
S We write that reaction as
Na2O + H2O  2 NaOH
Why does one react and the other
doesn’t?
S Well, that’s chemistry. It’s not all that
complicated but the answer won’t make
much sense right now.
S But, by the end of the course (Jan or June)
it will make a lot of sense.
NOW: STUDY HARD!!
15-30 minutes every night! After you do all
your reading and homework, etc.
If you do, you won’t end up looking like this
poor kitty the night before the test.
You should plan on studying hours for
But it
doesn’t all have to be done
the night before.
EVERY chemistry test.
What’s in it for YOU?
Start Time
End Time
Well, studies show that if
you review something
LATER THAT SAME
DAY (and that’s called
studying), you have an 80%
better chance of actually
remembering it.
Helpful Hints
S Take this class one step at a time.
S Read and outline the chapter. If you haven’t
already started doing Chapter 3, you are already
BEHIND! Don’t just copy what the book says
into your notes. Rewrite it in your words, so
you understand what you wrote.
S Know the VOCAB from the book. If you don’t
understand the words, you won’t know what I
am talking about.
Chemistry Builds on Itself
S If you don’t understand what we are doing today,
you aren’t going to get it tomorrow, because what
we learn tomorrow will depend on what we learned
today.
S You can’t do Chapter 19 until you’ve learned 1-18.
S Google if you don’t understand something! Ask
questions!
S Work with each other! Form study groups!!
It takes Time, and Work and
EFFORT!
SIt took over 250 years of hard
work by thousands of brilliant
scientists to “figure out”
Chemistry!
SHow are you going to learn it
in 5 minutes or once a week?
Chemistry (or Schwartz)
is too Hard or There’s Math in
Chemistry!
S It’s not.
S I’m not. But I can be if
you don’t do your job.
S Yeah, there is. Algebra
1. Lots of it.
S Sometimes, this will seem
This puzzle is UNSOLVABLE, but
Chemistry is SOLVABLE, if you work.
like your second math
class.
S Let’s do some math!
Density
S Anyone remember the
formula for density?
S Anyone remember the
“density heart?”
d=m/V
OMG, we just zoomed into Chapter 3
S Density equals mass divided by volume. That’s what the formula is
telling you. (Most of you probably already knew that).
S Density has units of “g/mL” or “g/cm3”
S Mass has units of grams (g).
Write this down
and learn it!
S Volume has units of milliliters (1 mL = 1cm3)
S But what does density really mean? Density tells you how much 1
milliliter (volume) is going to weigh.
S One mL of water weighs 1 g. One mL of gold weighs 19.3 g.
d=m/V
S If you know 2 of those 3 variables, you can solve for
(calculate) the remaining one. This is basic, basic
algebra 1.
S Rearrange the formula so that mass is by itself.
S Rearrange the formula so that volume is by itself.
d=m/V
S If you know 2 of those 3 variables, you can solve for
(calculate) the remaining one. This is basic, basic
algebra 1.
S Rearrange the formula so that mass is by itself.
S Rearrange the formula so that volume is by itself.
m=Vxd
d=m/V
S If you know 2 of those 3 variables, you can solve for
(calculate) the remaining one. This is basic, basic
algebra 1.
S Rearrange the formula so that mass is by itself.
m=Vxd
S Rearrange the formula so that volume is by itself.
V=m/d
d=m/V
S If you know 2 of those 3 variables, you can solve for
(calculate) the remaining one. This is basic, basic
algebra 1.
S Rearrange the formula so that mass is by itself.
m=Vxd
S Rearrange the formula so that volume is by itself.
V=m/d
S Write these into your notes.
d=m/V
S If you know 2 of those 3 variables, you can solve for
(calculate) the remaining one. This is basic, basic
algebra 1.
S Rearrange the formula so that mass is by itself.
m=Vxd
S Rearrange the formula so that volume is by itself.
V=m/d
S You don’t need to memorize all 3. Memorize the
top one and rearrange when you need one of the
others!
K = °C + 273
S This formula converts Celcius temperature into Kelvin temperature.
S This will be on the SOL.
S For some problems in Chemistry, we need to use Kelvin temperature.
S We don’t use Fahrenheit temp. If this is first semester, it’s probably
about 80°F outside (maybe 30°F it is second semester). But you do need
to know how to convert from Celcius to Kelvin (and vice versa).
S What is the formula if you want °C by itself ?
K = °C + 273
S This formula converts Celcius temperature into Kelvin temperature.
S This will be on the SOL.
S For some problems in Chemistry, we need to use Kelvin temperature.
S We don’t use Fahrenheit temp. If this is first semester, it’s probably
about 80°F outside (maybe 30°F it is second semester). But you do need
to know how to convert from Celcius to Kelvin (and vice versa).
S Answer:
°C = K − 273
Remember…
What you actually learned today is…
What you have left after you forgot all
the other stuff I told you.
Learning requires real effort on your
part. Some kids think “learning”
means “teaching yourself.”
They are right. I can’t MAKE you
learn. But, I am here to help you
learn!
The End