Transcript File - Chemistry

Chemistry EOC
Goal 1 and 2
home
• Please get out your reference table as
you will be directed to pull certain
information from it to help you solve
specific problems
home
Competency Goal 1
• The learner will develop abilities
necessary to do and understand
scientific inquiry (4 %)
home
Goal 1.01
• Design, conduct and analyze
investigations to answer questions
related to chemistry
You should be able to:
home
Goal 1.02
• Evaluate reports of scientific
investigations from an informed
scientifically-literate viewpoint
including considerations of:
home
Goal 1.03
• Evaluate experimental designs with
regard to safety and use safe
procedures in laboratory investigations:
-Use MSDS info
-Acid into water, like you oughter!
home
Competency Goal 2
• The learner will build an
understanding of the
structure and properties of
matter (34 %)
home
Goal 2.01
• Analyze the historical
development of the current
atomic theory
- Let’s take a deeper look
into this goal…
home
Describe the composition
of the atom
home
The Atom: From Philosophical Idea to Scientific
Theory
I look pretty
good for a
dude 2400
years old!!!
In Greek, the prefix "a" means "not" and
the word "tomos" means cut. Our word
atom therefore comes from atomos, a
Greek word meaning uncuttable.
home
Dalton’s Atomic Theory
1. All matter is composed of small
particles called atoms.
2. Atoms of a given element are
identical; atoms of different
elements are different
3. Atoms cannot be subdivided,
created, or destroyed.
4. Atoms of different elements
combine in simple whole-number
ratios to form compounds
5. Atoms are combined, separated, or
rearranged in chemical reactions
home
The Electron
JJ Thomson--1897
Plum Pudding Model
But the
atom is
Neutral!!!!
While studying electric
discharge in Cathode-ray
tubes, Thomson
discovered the electron!!!
home
The Nucleus
Ernest Rutherford--1908
Rutherford’s Gold Foil Experiment
In an attempt to build on Thomson’s
model, I discovered some amazing
stuff!!!
home
Notice 2 things:
1. Atom is made
up of mostly
empty space.
2. Electrons are
scattered
randomly!
Rutherford’s Atomic Model
home
Nucleus
Electrons
Neils Bohr--1913
home
Bohr Model of the Atom
The Bohr Model has the following features:
1. There is a nucleus(Rutherford’s Discovery)
2. The electrons move about the nucleus in “stationary, stable
states”(later referred to as orbits)!
home
The Wave Model of the Atom
home
Discovery of the neutron
James Chadwick--1932
In 1932, Sir James
Chadwick, working
to interpret the
results of other
scientists,
discovered the
neutron!!!
home
Democritus/Dalton
home
Goal 2.02
• Examine the nature of atomic structure
Subatomic
Particle
Proton
Relative Mass
Charge
Where Found
1
+1
In Nucleus
Neutron
1
0(neutral)
In Nucleus
Electron
1/2000 or 0
-1
Outside
nucleus in
electron cloud
home
• Atomic # (Z) – Number of protons
• Mass # (A) – Number of protons + neutrons
– Also found by rounding the average atomic
mass
Same # protons, different # NEUTRONS
home
Atomic #
Atomic Mass
A # = 27
M # = 59
# p = 27
# e = 27
# n = 32
M#=#p+#n
59 = 27 + #n
home
2 ways of writing Isotopes
H-1 H-2 H-3
• Each of these
represents Hydrogen
• The number represents
the mass #
• Each of these represents
Carbon
• The top # represents the
mass #
• The bottom # represents
the Atomic #
home
Goal 2.03
• Apply the language and symbols of chemistry
• Be able to name:
– Ionic compounds
– Covalent compounds
– Polyatomic ions
Number
Prefix
1
Mono-
2
Di-
3
Tri-
4
Tetra-
5
Pentahome
Name these:
•
•
•
•
•
•
•
•
CaCl2
S2O5
PO43K2SO4
PO3
FeS
C2H3O2Ba(OH)2
Take your time to look
up the names of the
elements and
polyatomic ions!
home
A few more things you should know:
• The names of the following acids:
– HCl
– HNO3
– H2SO4
– CH3COOH or HC2H3O2
– And all of the symbols: (s), (g), (l), (aq), etc.
home
Goal 2.04
• Identify substances using their physical
properties:
Most of this information can be obtained
directly from the reference tables
home
Some examples include:
•
•
•
•
•
•
Melting point
Boiling point
Specific heat
Density
Solubility rules
And much more
• You could be told an unknown substance has a
specific heat of 0.129 J/g˚C … what is it?
home
Levels of Saturation
Saturated solution—Solution has dissolved
all the solute possible
Unsaturated solution—solution “could”
dissolve more solute.
Supersaturated solution—Solution has
dissolved all solute possible, but more
solute is added anyway.
*** Don’t forget… LIKE DISSOLVES LIKE
home
How many
grams of KNO3
will dissolve in
100 g of water
at 60o C?
110 g
home
At what
temperature will
approximately 95
g of NaNO3
dissolve in 100 g
of water?
30 oC
home
At what temperature
will the same amount
of KNO3 and NaNO3
dissolve in 100 g of
water?
~ 68 oC
home
Which term would describe a
solution of 90 g of KCl
dissolved in 100 g of water at
80 oC?
Unsaturated
Saturated
Supersaturated
Can’t but about 50 g
dissolve at 80 oC.
home
Suppose 90 g of KI are
placed in 100 g of water
at 10 oC. What type of
solution would you have?
Unsaturated
Saturated
Supersaturated
Could dissolve
about 135 g.
home
Approximately, how
much NH4Cl would
dissolve in 200 g of
water at 70 oC?
Twice as much
solute, because
twice as much
solvent!!!
120 g
home
Effects of Temperature on Solubility
Gases in liquidsAs temperature increases, the solubility
decreases.
Solids in liquids –
As temperature increases, the solubility
increases.
home
Goal 2.05
• Analyze the basic assumptions of
kinetic molecular theory and its
applications.
home
The Combined Gas Law
• Page 3 of your
reference table
Also, know proportionality
home
Tips for working gas law problems:
• 1.
• 2.
• 3.
• 4.
home
Ideal Gas Equation
PV = nRT
, where…
P is pressure
V is volume
n is number of moles
R is the Ideal gas constant
T is the temperature
You always have this!!!
home
Dalton’s Law of Partial Pressures
• PT = P 1 + P 2 + P 3 …
• Page 3 of your reference table
• Remember, if a gas is collected
over water, you have to account
for water vapor pressure
***Conceptual understanding,
calculations
home
Goal 2.06
• Assess bonding in metals and ionic
compounds as related to chemical and
physical properties
• Ionic compound properties: high BP,
high MP, high electrical conductivity (in
molten or aqueous state, brittle
home
Do you remember why atoms
bond?
home
Ionic Bond
• Gain or loss of electrons to form ions
--Electrostatic attraction between
metals and nonmetals
home
Oxidation #
home
Metallic Bond
• “Sea of Electrons”
• Form between a
metal and metal
High luster, malleable,
ductile, high
conductivity, high MP,
high BP
home
Goal 2.07
• Assess covalent bonding in molecular
compounds as related to molecular
geometry and chemical and physical
properties.
home
Covalent Bond
• Sharing of electrons to form a compound
that is stable (octet rule)
-- Forms between nonmetal and nonmetal
home
What type of bond forms
between each of these pairs?
•
•
•
•
•
•
•
Sodium and bromine
Ammonium and chlorine
Zinc and copper
Oxygen and oxygen
Sulfur and oxygen
Hydrogen and chlorine
Gold and gold
You also need to know the
properties of ionic and
covalent compounds!
home
Ionic vs. Covalent Compounds
Ionic Compounds
Covalent Compounds
• Hard, but brittle
• High MP and BP
• Many can dissolve in
water
• Conductors in
molten state
•
•
•
•
Soft
Lower MP and BP
Good insulators
Mostly gases at
room temp.
home
You must know the diatomics:
• There are seven
of them
• Also, know
which ones
form single,
double, and
triple bonds
home
Bond Energy vs Bond Length
Bond Energy
Bond Length
Triple > double > single
Single > double > triple
Do you know why this is true?
home
VSEPR
• What does VSEPR stand for?
• Can you name the geometry,
hybridization, and bond angle for each
of the above molecules?
home
Lewis Dot Structures
• The two things you have to remember in
drawing covalent molecules are that:
• 1. You have to satisfy the octet rule
– Except hydrogen and helium
• 2. You have to make sure you have the
right number of electrons
home
Are these molecules polar, and if so, in which
direction is the net dipole?
home
Covalent-Network
Compounds
• Covalent compounds that do not contain
individual molecules, but instead can be
pictured as continuous, 3-D, networks of
bonded atoms
home
Intermolecular Forces
• Hydrogen Bonds
• London Dispersion Forces
home
Goal 2.08
• Assess the dynamics of physical
equilibria
home
Heating Curve
• Can you change temperature and phase
at the same time?
home
Know these:
home