Transcript acids and bases DRB - Hawthorne High School

Init <<5/12/2008 by Daniel R. Barnes
WARNING: This presentation includes a combination of original graphical images created by the author and images taken
without specific permission from the world wide web. Do not distribute or copy this presentation.
CAUTION: This author uses Wikipedia as though it could be trusted. Uh-BUGGA-BUGGA-BUGGA-BUGGA-BOO!
I looked, but I saw nothing in the NGSS that specifically
stated that high school students needed to learn general
princples about acids and bases.
Gulp™?
SWBAT . . .
. . . list the observable
properties of acids, bases,
and salt solutions.
And NO CONTACT
LENSES on lab
days!
Okay, well, maybe I
am irritating, but I’m
not corrosive.
No, wait, I’m not the
corrosive & irritating
one.
Just remember to
wear your goggles
during labs, okay?
ACIDS and BASES
are corrosive and
irritating.
How long are you supposed to wash your eyes out if you get
acids or bases or anything else in them?
According to the Flinn Scientific Student Safety Contract that
you should have signed by now . . .
Too bad we don’t have
a second pair of
hands on our faces
like this. If we did, we
could use our regular
hands to keep the
eyewash handle
turned on. Since we
don’t have face
hands, you’ll need a
buddy to keep the
eyewash fountains
turned on while you
hold your eyes wide
open with your
fingers.
“When acid comes into contact with the body it feels like water.
It wets the body and a burning sensation begins that gradually
increases in intensity. The patients cry in agony until the
chemical is washed away or is neutralized. The affected skin
becomes black and leather-like. The chemical also leaves its
mark on the healthy skin it trickles over”
http://www.burnsurgery.org/Betaweb/Modules/initial/part_two/sec6.htm
Alkali burn
sodium hydroxide burn
http://www.enotes.com/topic/Chemical_burn
Acid “cooks” flesh.
BASE
ACID
Bases
taste
bitter.
Acids
taste
sour.
Acids, bases, and salts are all electrolytes,
although some are strong and some are weak.
-+ +
+
- +- +
+
- - +
pure water
electrolyte = ?
(has freely wandering ions) (a non-electrolyte)
Acids react with
metals, corroding the
metals to form salt
and hydrogen gas.
Acid + metal 
Salt + hydrogen gas
Acids are typically
stored in glass or
plastic containers.
You’ll probably never
see an acid stored in a
metal container.
Bases can corrode metal too:
http://www.hbscc.nl/publications/23%20alkaline/alkaline2.htm
Acids are more famous for being metaldestroyers, but bases are known for
attacking metal in some cases, also.
http://www.youtube.com/watch?v=WnPrtYUKke8
&feature=youtube_gdata_player
Thank you, Roberto Pinzon, for giving me this link.
HS-PS-2. Construct and revise an explanation for the
outcome of a simple chemical reaction based on the
outermost electron states of atoms, trends in the periodic
table, and knowledge of the patterns of chemical
properties.
METAL HYDROXIDES tend to be BASES.
Alakali metals react with water to form metal hydroxides.
2Li + 2H2O  H2 + 2LiOH
Q: What is the formula of
the hydroxide ion?
2Na + 2H2O  H2 + 2NaOH
A: OH-
2K + 2H2O  H2 + 2KOH
Q: Why do alkali metals
form hydroxides?
A: Alkali metals have one
2Rb + 2H2O  H2 + 2RbOH
valence electron, so they
like to lose it to empty
their outer shell, rendering
2Cs + 2H2O  H2 + 2CsOH
them positive, which
attracts them to negative
2Fr + 2H2O  H2 + 2FrOH (?) ions like hydroxide.
alkali burn
fun at the beach!
HCl + NaOH  NaCl + H2O
Acid burn
ACID + BASE  SALT + WATER
(usually)
Q: How do acids and bases taste?
A: Acids taste sour. Bases taste bitter.
Q: Acids and bases may be opposites, but what do they have
in common?
A: They are both corrosive and irritating. They are both
electrolytes.
Q: Why is red the symbolic color for acids and blue the
symbolic color for bases in this presentation?
A: Acids turn litmus paper red and bases turn it blue.
Q: What is produced when an acid reacts with a base?
A: Salt and water.
Q: What is produced when an acid reacts with a metal?
A: Salt and hydrogen gas.
SWBAT . . .
. . . Define acids and bases
in terms of ion donation
and acceptance.
OH
+
H
Acid: a substance
that gives off H+ ions
in water.
HCl  H+ + Cl-
H+ = “hydrogen ion”
Svante Arrhenius
1859-1927
Base: a substance
that gives off OH- ions
in water.
NaOH  Na+ + OHOH- = “hydroxide ion”
1
H
Hydrogen
1.01
All that’s left is
just a single,
lonely . . .
+
When it had an
electron, it was a
hydrogen atom
. . . proton.
+
H
Now that it’s lost
its electron, it
has become a
hydrogen ion.
1
H
Hydrogen
1.01
+
+ = proton
H
+
H
H 2O
OH
Acid: a substance
Base: a substance
that gives off H+ ions
that gives off OH- ions
in water.
in water.
Looking at these definitions of “acid” and
“base”, one gets the idea that water is
“normal”, “neutral”, and “average”, that it is
the “middle chemical”. However, I have a
nagging feeling that aliens from other planets
may not share our view . . .
My drink’s getting
a little low. You
got anything to
top it off with?
No.
God
no!
Are you
trying to
poison me?
Now
you’re
talking!
Speaking of
ammonia . . .
NH3 is a base, but
where’s the OH?
NH3 + H2O  NH4+ + OHJohannes
Bronsted
Thomas
Lowry
NH3 doesn’t give OH-,
but it does take H+.
Acids donate hydrogen ions.
Bases accept hydrogen ions.
Honors students,
you are required to learn
about
Lewis acids and Lewis bases
on your own
(to the degree that we fail to
cover it in class).
Q: According to Svante Arrhenius, what is the definition of
an acid?
A: An acid is a chemical that gives off H+ ions in water.
Q: What was his definition of a base?
A: Arrhenius said a base was a chemical that gave off OHions in water.
Q: What is the Bronsted-Lowry definition of acids and
bases?
A: Acids give H+ ions. Bases take H+ ions.
SWBAT . . .
. . . Explain how
the self-ionization of water
relates to Kw
If this is a non-honors
chemistry section, or if you’re
simply pressed for time,
please skip to pH. Honors
students are required to learn
about Kw on their own even if
there’s no time in class.
Our notions of
(at least the older definitions of “acid” and “base”)
are prejudiced by the fact that Earth is a mostly watercovered planet
and, that, consequently, Earth’s creatures, including people,
are made mostly of water.
Water molecules are very stable.
Nonetheless, every once in a while, a water molecule breaks
in two.
H2O
H+
+
OH-
The hydrogen and hydroxide ions that water breaks into like
each other a lot because of their opposite charges, so they
get back together again pretty fast.
Therefore, the equation for the dissociation of water deserves
a double arrow, since it is a reversible reaction.
Because water molecules rarely break, and because they get
back together again so quickly when they do break, the
amount of broken molecules in a quantity of pure water is
very low.
H2O
> 99.9%
H+
+
OH-
<< 1%
The percentages listed here are quite rough. We can be even
more precise if we want to.
Because water molecules rarely break, and because they get
back together again so quickly when they do dissociate, the
amount of broken molecules in a quantity of pure water is
very low.
H2O
> 99.9%
H+
+
OH-
<< 1%
The percentages listed here are quite rough. We can be even
more precise if we want to.
H+
+
OH-
In pure water,
the concentration of
broken water molecules is
10-7M
That’s the same thing as
10-7 mol/L
10-7 mol/L = 0.0000001 mol/L
One liter (L) of water has a mass of 1000 g.
The molar mass of water is 18 g/mol.
(1000 g)/(18 g/mol) = 55.6 mol, so the concentration of water
in water is 55.6 mol/L.
(55.6 mol/L)/(10-7 mol/L) = 556,000,000
In pure water,
only one out of every 556,000,000 water molecules is broken.
H+ +
OH-
In pure water, only
one out of every 556,000,000
water molecules
is broken.
That’s about 0.002 ppm
H2O
H2O + H2O
H+ + OH-
H3O+ + OH-
Unless disturbed, aqueous (watery) systems, such as a cup
of water, an ocean, a car battery, or your bloodstream, will
tend reach a state of equilibrium, in which the forward and
reverse reactions shown below occur at equal rates.
H2O
Equilibrium:
H+
+
OH-
when opposite processes occur at equal rates.
Amounts of different chemicals are probably not equal to
each other.
However, at equilibrium, the amount of each chemical does
not change as time goes by.
At equilibrium, water molecules fall apart but they come back
together again just as quickly as they fall apart.
LeChatelier’s Principle
H2O
H+
+
OH-
If a system is at equilibrium, the amount of each chemical will
remain constant as time goes by.
However, if a system at equilibrium is disturbed by some kind
of stress, the reaction rates will change in whatever way will
oppose the effects of the disturbance.
If a bunch of molecules are at equilibrium and you disturb
them, the molecules will try to undo the work you have done.
LeChatelier’s Principle
H2O
+ OHH+
Imagine a bathtub full of water. If not disturbed, it will reach
an equilibrium with regard to the above reversible reaction.
H+ = 3
OH- = 3
LeChatelier’s Principle
H2O
+ OHH+
However, if you raise the [H+], say, by pouring in some
hydrochloric acid, this will disturb the equilibrium.
Didn’t you see us
being in equilibrium?
RUDE!
Sa-kurity!
Oh no you di-ent
just add more H+!
H+ = 3 6
OH- = 3
LeChatelier’s Principle
H2O
+ OHH+
The system will now do whatever it takes to lower the [H+], to
undo what you just did . . . at least partially . . .
H+ = 3 6
OH- = 3
LeChatelier’s Principle
H2O
+ OHH+
The equilibrium, as they say, will “shift to the left”. Why?
The forward reaction creates H+, but the reverse reaction
(going to the left) uses up H+, turning it into water.
Did you notice that by
adding H+, you made
OH- decrease?
H+ = 3 6 4
OH- = 3 1
It is generally true that if you make [H+] increase, you will
cause a decrease in [OH-].
This is expressed mathematically by the following equation:
[H+][OH-] = 10-14M2
If two numbers always multiply to give the same result, then
when one of the two numbers gets bigger, the other must get
smaller. Take the following example:
1 x 24 = 24
2 x 12 = 24
3 x 8 = 24
4 x 6 = 24
6 x 4 = 24
It is generally true that if you make [H+] increase, you will
cause a decrease in [OH-].
This is expressed mathematically by the following equation:
[H+][OH-] = 10-14M2
Now try some acid-base examples. These examples could be
any aqueous (watery) system.
If [H+] = 10-3M, then [OH-] = 10-11M
1 x 24 = 24
2 x 12 = 24
If [H+] = 10-12M, then [OH-] = 10-2M
If [H+] = 10-1M, then [OH-] = 10-13M
3 x 8 = 24
4 x 6 = 24
6 x 4 = 24
If [H+] = 10-7M, then [OH-] = 10-7M
If [H+] = 1M, then [OH-] = 10-14M
SWBAT . . .
. . . use the pH system to
characterize acid, base, and
salt solutions.
-
+
0
7
14
Click the link below to an FDA web
page listing pH’s of different foods.
http://www.engineeringtoolbox.com/
food-ph-d_403.html
According to this web page, what is
the overwhelming tendency for the
pH of foods?
Foods tend to be . . .
. . . the esoteric version . . .
“pH” stands for “potential hydrogen”. (maybe)
pH is a weird, numerical way of showing the hydrogen
ion concentration in a solution.
Mathematically, pH = -log[H+]
That’s slightly confusing even if you know what logs are.
log(10n) = n
log(1000) = 3
log(10) = 1
log(1,000,000) = 6
log(100) = 2
log(50) = 1.6987. . .
log(0.1) = -1
log(1) = 0
log(0.0001) = - 4
log(1013) = 13
log(10-5) = -5
Let’s give an example of pH: normal water.
In normal water, the hydrogen ion concentration is 10-7M.
In other words, [H+] = 10-7M.
Since pH = -log[H+] . . .
The pH of normal water would be 7.
In sea water, however, the pH is 8.
What would the hydrogen ion concentration be in sea water?
In sea water, [H+] = 10-8M.
That’s a little more basic than pure water.
H2SO4
Car batteries are filled with very dangerous sulfuric acid.
In battery acid, one of the most corrosive acids there is,
the hydrogen ion concentration is about 1M.
1 = 100, so . . .
In battery acid, the pH is . . . 0
Lemon juice is one of the most acidic foods you can eat.
In lemon juice, the hydrogen ion
concentration is about 10-2M.
In lemon juice, the pH is . . . 2
That’s not as strong as battery acid,
but it can still rot your teeth.
Sodium hydroxide is a strong base.
It’s also known as “lye” and turns fat into soap,
which makes it a handy drain opener.
In a concentrated sodium hydroxide solution,
the hydrogen ion concentration can be about 10-14M.
In such a concentrated solution of sodium hydroxide,
the pH is . . . 14
A typical pH for vinegar is 3.
What would the hydrogen ion concentration be in vinegar?
In vinegar, [H+] = 10-3M.
That’s not quite as acidic as lemon juice or battery
acid, but that’s still pretty sour.
High [H+]
Low pH
+
H
Low [H+]
High pH
High [OH-]
Low pOH
OH
Low [OH-]
High pOH
It is generally true that if you make [H+] increase, you will
cause a decrease in [OH-].
This is expressed mathematically by the following equation:
[H+][OH-] = 10-14M2
Now, just for fun and review, tell me the pH for each of the
following solutions, and tell me if it’s acid, base, or neutral.
pH = 3 (acid)
If [H+] = 10-3M, then [OH-] = 10-11M
pH = 12 (base)
If [H+] = 10-12M, then [OH-] = 10-2M
pH = 1 (acid)
If [H+] = 10-1M, then [OH-] = 10-13M
pH = 7 (neutral)
If [H+] = 10-7M, then [OH-] = 10-7M
pH = 0 (acid)
If [H+] = 1M, then [OH-] = 10-14M
pH + pOH = 14
If the pH of a concentrated sodium hydroxide solution is 14,
Then the pOH is . . . zero
Low pH = acid (<< 7)
High pOH
pH of 7 = neutral (like water)
Medium pOH
High pH = base (>7)
Low pOH
High [H+] or low [H+]?
Example #1
High [OH-] or low [OH-]?
High pH or low pH?
High pOH or low pOH?
H+
H+
Acid, base or neutral?
H+
H+
H+
H+
OH-
H+
High [H+] or low [H+]?
Example #2
High [OH-] or low [OH-]?
High pH or low pH?
High pOH or low pOH?
H+
H+
OHH+
OH-
Acid, base or neutral?
OHOH-
OH-
OH- OH-
H+
+] or low [H+]?
High [Hmedium
Example #3
-] or low [OH-]?
High [OHmedium
medium
High pH
or low pH?= 7
High pOH
or low pOH?= 7
medium
H+
OH-
OHH+
OH-
H+
OH-
H+
OHH+
Acid, base or neutral?
Q: What is “[H+]”?
A: [H+] = hydrogen ion concentration, in mol/L
Q: What is the mathematical definition of pH?
A: pH is -1 times the log of hydrogen ion concentration.
In other words, pH = -log[H+]
Q: What kinds of materials have what kinds of pH’s?
A: Acids have pH’s less than 7, bases higher than 7, neutral
materials (like pure water) equal to 7.
Q: What kinds of pH’s do you get when [H+] is low and when
[H+] is high?
A: Low [H+]  high pH. High [H+]  low pH.
Q: What is the relationship between pH and pOH?
A: pH + pOH = 14; low pH means high pOH & vice versa.
SWBAT . . .
. . . define what “strong”
and “weak” mean when
used to describe acids and
bases.
H molecule that
Cl HCl
H splits
Every single
water
Cl H enters theCl
up
H ions.
Clinto
Therefore, HCl is considered to be a “strong” acid.
Cl H
Cl H
Cl H
-
-
+
-
-
+
+
+
-
+
-
+
-
+
H
H
H
H
O
Only
of
the
CH
COOH
molecules
O splitHinto ions.
O O
O some
3
O
O
O
O O
In fact,
most
of
them
did not. C
C
C
C
CH3COOH is a “weak acid”.
C
H
C
H C
H C
H
H
H
H
C
H
H
H
CH
H
H
H
H
+
-
STRONG
ACIDS:
HCl
H2SO4
HBr
HNO3
HI
HClO4
WEAK
ACIDS:
HF
anything
with COOH
HF + H2O  F- + H3O+
all other
acids
H2SO4
H3PO4
CH3COOH
HCl
HNO3
CH3(CH2)16COONa
NaOH
NaHCO3
NH3
KOH
NH4OH
Ca(OH)2
HOOC–CH2–COH(COOH)–CH2–COOH
hydrochloric acid
Hacetic
H3PO4
2SO4 acid
CH3COOH
HCl
“monoprotic”
HNO3
CH3(CH2)16COONa
NaOH
5%
NaHCO3
NH3
KOH
NH4OH
Ca(OH)2
HOOC–CH2–COH(COOH)–CH2–COOH
85%
H2SO4
H3PO4
CH3COOH
HCl
HNO3
CH3(CH2)16COONa
NaOH
NaHCO3
NH3
KOH
NH4OH
Ca(OH)2
HOOC–CH2–COH(COOH)–CH2–COOH
diprotic
H2SO4
H3PO4
sulfuric
CH3COOH
acid
“weak”
HCl
CH3(CH2)hydronium
16COONa
ion
NaHCO3
NaOH
NH3
KOH
HNO3
NH4OH
Ca(OH)2
HOOC–CH2–COH(COOH)–CH2–COOH
H3O+
“STRONG”
http://www.youtube.com/watch?v=100Bk580mPY&feature
=youtube_gdata_player
Don’t be fooled by the H3.
H3PO4 may be
“triprotic”,
H2SO4but H3PO4
none of the H’s
come off
CH3COOH
easily.
HCl
HNO3
H3PO4 is a strong molecule,
so it is a “weak” acid.
CH3(CH2)16COONa
phosphoric acid
NaHCO3
NaOH
NH3
KOH
NH4OH
Ca(OH)2
HOOC–CH2–COH(COOH)–CH2–COOH
methyl
group
carboxylic
acid group
H
H C H
C
O
O
H
formula?
C2H4O2
acetic acid
ethanoic acid
CH3COOH
H2SO4
H3PO4
CH3COOH
HCl
HNO3
CH3(CH2)16COONa
NaOH
NaHCO3
NH3
KOH
NH4OH
Ca(OH)2
HOOC–CH2–COH(COOH)–CH2–COOH
nitric acid
H2SO4
H3PO4
CH3COOH
HCl
CH3(CH2)16COONa
NaOH
NaHCO3
NH3
KOH
HNO3
NH4OH
Ca(OH)2
HOOC–CH2–COH(COOH)–CH2–COOH
721-815 AD
nitric acid
Abu Musa Jābir ibn Hayyān
O
H
H
C
O
O
O
H2SO4
H3PO4
C
?
H
?
C
CH?
O
3COOH
H
HCl
O
HNO3
H
H
CH3(CH2)C16COONa
C
NaOH
C
H
NHH3
O
NaHCO3
KOH
citric
acid
Ca(OH)
NH4OH
2
HOOC–CH2–COH(COOH)–CH2–COOH
Metal hydroxides are
sodium
hydroxide
CH
(CH
)
COONa
generally
bases.
3
2
16
H2SO4
H3PO4
Group 1A & 2A metals are
NaHCO3
NaOH
especially famous for
CH3COOH
reacting
with water to form
KOH
NH3
alkaline solutions.
HCl
HNO3
NH4OH
Ca(OH)2
HOOC–CH2–COH(COOH)–CH2–COOH
sodium
stearate
H2SO4
H3PO4
CH3COOH
HCl
HNO3
CH3(CH2)16COONa
NaOH
NaHCO3
NH3
KOH
NH4OH
Ca(OH)2
+
HOOC–CH2–COH(COOH)–CH2–COOH
H2SO4
H3PO4
CH3COOH
HCl
HNO3
CH3(CH2)16COONa
NaHCO
NaOH
3
ammonia
KOH
NH3
Ca(OH)2
HOOC–CH2–COH(COOH)–CH2–COOH
NH3 is a base.
According to Arrhenius, though, it can’t be a base. Why?
It has no OH to give off. But all experimental
evidence shows that ammonia is a base. ???!!!
NH3 + H2O  NH4+ + OHNH3 is a gas when pure, but, it dissolves in water
very readily. When it does, some of the ammonia
molecules even steal protons from water!
Stealing protons is the opposite of giving protons, so
ammonia is the opposite of an acid.
Ammonia is a base. Ammonia is a weak base.
Johannes
Bronsted
Thomas
Lowry
Acids donate hydrogen ions.
Bases accept hydrogen ions.
H2SO4
H3PO4
CH3COOH
HCl
HNO3
CH3(CH2)16COONa
NaHCO
NaOH
3
ammonia
KOH
NH3
Ca(OH)2
HOOC–CH2–COH(COOH)–CH2–COOH
ammonium
NH4OH
hydroxide
H2SO4
H3PO4
CH3COOH
HCl
HNO3
CH3(CH2)16COONa
NaOH
NaHCO3
NH3
KOH
NH4OH
Ca(OH)2
HOOC–CH2–COH(COOH)–CH2–COOH
Q: What is the difference between a monoprotic acid, a
diprotic acid, and a triprotic acid?
A: A monoprotic acid has one H+ to give away. A diprotic
acid has two H+’s to give away. A triprotic acid has three.
Q: When you see “COOH” in a formula, what does this
indicate?
A: The chemical is a weak acid.
Q: What is the difference between a strong acid and a weak
acid?
A: Strong acids completely dissociate in water. Weak acids
do not. (Same thing for strong vs weak bases.)
Q: How many strong acids are there? Name them.
A: Six: HCl, HBr, HI, H2SO4, HNO3, HClO4.
SWBAT . . .
. . . Predict and explain
the outcome of acid-base
neutralization reactions.
sodium hydrogen
carbonate
CH
(CH
)
COONa
3
2
16
H2SO4
H3PO4
NaHCO3
NaOH
CH3COOH
KOH
NH3
HCl
HNO
+ 3
NH4OH
Ca(OH)2
HOOC–CH2–COH(COOH)–CH2–COOH
BASE
NaHCO3
+
ACID
CH3COOH
WATER
SALT
NaCH3COO + CO2 + H2O
Acids and bases neutralize each other, turning into salt
and water in the process.
HCl + NaOH  NaCl + H2O
HCl + KOH  KCl + H2O
HBr + CsOH  CsBr + H2O
H2SO4 + Cu(OH)2  CuSO4 + 2H2O
CH3COOH + NaOH  NaCH3COO + H2O
CH3COOH + RbOH  RbCH3COO + H2O
H2CO3 + 2LiOH  LiHCO3 + LiOH + H2O  Li2CO3 + 2H2O
H2CO3 + Ca(OH)2  CaCO3 + 2H2O
H2SO4 + Mg(OH)2  MgSO4 + 2H2O
Acids and bases neutralize each other,
turning into salt and water.
ACID
WATER
HCl + NaOH
NaCl + H
BASE  SALT
2O
ACID
HCl + BASE
KOH  SALT
KCl + HWATER
2O
SALT + H
BASE  CsBr
WATER
HBr + CsOH
ACID
2O
WATER
SALT 4 + 2H
BASE 2  CuSO
HACID
2SO4 + Cu(OH)
2O
SALT
BASE  NaCH
CHACID
H2O
3COOH + NaOH
3COO + WATER
SALT
BASE  RbCH
CHACID
WATER
3COOH + RbOH
3COO + H
2O
WATER
BASE  LiHCO3 + LiOH + H2O  LiSALT
HACID
2CO3 + 2LiOH
2CO3 + 2H
2O
SALT 3 + 2H
BASE 2  CaCO
WATER
HACID
2CO3 + Ca(OH)
2O
SALT
BASE
WATER
HACID
2SO4 + Mg(OH)2  MgSO4 + 2H
2O
SWBAT . . .
. . . recall that proteins are
polymers made of amino
acid monomers.
Protein is a polymer made of amino acid monomers.
amino
acid
amino
acid
amino
acid
amino
acid
amino
acid
amino
acid
amino
acid
amino
acid
amino
acid
amino
acid
amino
acid
amino
acid
An amino acid
can neutralize
itself.
H
?
“Amino” refers to
ammonia.
Ammonia = NH3.
amino
N
It’s part acid,
part base.
The name
“amino acid”
is kind of
misleading.
H
C H
“Amino acid”
sort of means
“base acid”.
C
O
O
+
H
H
amino acid
acid
Ammonia is a
base.
We’ll learn more about amino acids in our next unit . . .
. . . ORGANIC CHEMISTRY.
Until then . . .
Okay, now it’s probably time to
* Turn in the Chapter 19 Packet.
* Take the Ch 19 Quiz
Next meeting, there may be a lab.
Dress for lab next meeting.
(No contact lenses, no sandals, etc..)
B’dee-uh
b’dee-uh
b’dee-uh
That’s all
folks!