Upload
helene
View
70
Download
4
Tags:
Embed Size (px)
DESCRIPTION
Chemistry Survival Guide. A Visual Guide to Understanding Chemistry. Table of Contents. Intro to Chemistry. Nuclear Chemistry. Atomic Structure. Gas Laws. Periodic Table. Thermochemistry. Compounds. Solutions. Quantitative Chemistry. Acids & Bases. “Chemistry in the Real World”. - PowerPoint PPT Presentation
Citation preview
A Visual Guide to Understanding Chemistry
Intro to Chemistry
Atomic Structure
Periodic Table
Compounds
Quantitative Chemistry
Gas Laws
Nuclear Chemistry
Thermochemistry
Solutions
Acids & Bases
“Chemistry in the Real World”
The science community* has increasingly identified the content focus and the instructional practices as the two areas most in need of change (McCleery & Tindal, 1999).
*(National Science Teachers Association, the American Association for the Advancement of Science, and the National Science Foundation Education Association)
Focusing the Content
Sequencing Activities
Minimizing Learner Demands
Teaching in Small Steps
Guiding Students During Initial Practice
Providing High Levels of Successful Practice
Flexible Curricula
Multiple Representations of Presented Information
Multiple Means of Expression and Control
Multiple Means of Motivating and Engaging Students
(Orkwis, 1999)
Intensified:
Theme-Based:
Hands-On
Long Term Activities
Interrelationships Among Unifying Processes
(Cawley, Foley, & Miller, 2003)
Classifying Matter
Accuracy & Precision
Calculating Percent Error
Metric System & Unit Conversion
Scientific Notation
Physical vs. Chemical Properties
Pure Substances Mixtures & Compounds
Calculating Density
Matter
Substance Mixture
Element Compound Hetero geneous
Homo geneous
MatterAnything with Mass & Volume
SubstanceMatter with a constant composition, wherever it is found
Mixture
Matter with variable composition that is physically combined
ElementMade up of only one atom
CompoundTwo or more elements chemically combined
HeterogeneousMade up of more than one phase
HomogeneousMade up of only one phase, considered uniform
DENSITY: A physical property of matter, measured in: grams, or g/ml or g/cm3
D = M/V Density = Mass divided by Volume (g or g/ml or g/cm3)
M = D V Mass = Density times Volume (in grams)
V = M/D Volume = Mass divided by Density ( in ml, l,
cm3)
V = LWH Volume = Length times Width times Height
(cm3)
Density = Mass / Volume
Mass = Density x Volume
Volume = Mass / Density
G MG X 1000
G CG X 100
MG G X 1/100
CG G X 1/100
L ML X 1000
M L 1000
M KM 1000
KM M X 1000
PREFIX DECIMAL EQUIVALENT
EXPONENTIAL EQUIVALENT
Pico 0.000000000001 10-12
Nano 0.000000001 10-9
Micro 0.000001 10-6
Milli 0.001 10-3
Centi 0.01 10-2
Deci 0.1 10-1
Kilo 1000.0 10 3
Mega 1,000,000. 10 6
Giga 1,000,000,000.0 10 9
10+ 10
Move Decimal point # of times to left
Move Decimal point # of times to right
6028 L = 6.028 x 103 L 0.006L = 6 x 10 -3 L
PHYSICAL CHEMICAL
Can be measured w/o changing the chemical nature of the substance from one state to another
Can be observed when matter is altered, and undergoes a irreversible change
Mass, Volume, Density, Area, Length, Emission of Light, Absorption of Heat/Cold, Melting & Boiling point, Color
Evolution of a Gas (fizzles, bubbles) Forming a Precipitate (solid)
Aluminum foil is cut in half. Milk goes sour.
Clay is molded into a new shape. Jewelry tarnishes.
Butter melts on warm toast. Bread becomes toast.
Water evaporates from the surface of the ocean.
Rust forms on a nail left outside.
A juice box in the freezer freezes. Gasoline is ignited.
Rubbing alcohol evaporates on your hand.
Hydrogen peroxide bubbles in a cut.
Ice melting Food scraps are turned into compost in a compost pile.
A Diamond cutting glass A match is lit.
You take an antacid to settle your stomach.
Your body digests food.
You fry an egg
Pure Substances Mixtures Compounds
Can be element or compoundContains only one type of
substance
Can be element or compound
Combinations of other pure substances
Contain two or more elements bonded together chemically. The chemical formula contains two or more capital letters
Has fixed definite composition No Definite ratio ALWAYS a definite ratio
Can be separated physically Can ONLY be separated chemically
A physical blend
Atomic Structure
Atomic Scientists
Orbital Filling Diagram
Atoms are indestructible, indivisible, and identical.
Combine in simple ratios called the Law of Definite Proportions.
Atoms are not created or destroyed during a reaction.
Cathode Ray tube experiment
Plum Pudding model
Opposite charged particles (electrons) attract
Alpha Particles and Gold Foil experiment
Atoms are mostly “empty space”
Nucleus is small but has almost all of atom’s mass
Planetary model
Electrons occupy specific orbits around the nucleus
Particle Charge Mass Location
Proton + 1 Nucleus
Electron - 0 Orbital/Ring/cloud
Neutron No Charge 1 Nucleus
1S22S22P4
ALUMINUM Z=13 1S2 2S2 2P6 3S2 3P1
1S2
2S2
2P6
3S2
3P1
Protons, Electrons & Neutrons
Periodic Table of the Elements
Periods & Groups
Blocks
Trends
Ions
Atomic Number = Number of Protons
Number of Protons = Number of Electrons
Mass Number – Atomic Number = Number of Neutrons
# of P’s = # of E’s
Mass # - Atomic # = # of N’s
Arranged vertically in GROUPS
Arranged horizontally in PERIODS
Arranged in BLOCKS (S, D, P, F)
S
D P
F
Atomic Radius &
Metallic Character
Ionization Energy
&
Electronegativity
INCREASES DOWN A GROUP
DECREASES ACROSS A PERIOD INCREASES ACROSS A PERIOD DECREASES DOWN A GROUP
1+
Group 1
2+
Group 2
3+
Group 13
3-
Group 15
2-
Group 16
1-
Group 17
Binary Ionic Compounds
Bonding
Writing Formulas
Lewis Dot Structures
IONIC COMPOUNDS:
NAMING BINARY IONIC COMPOUNDS:
Any chemical compound that is composed of oppositely charged ions
The name of the CATION followed by The name of the ANION + IDE
NAMING BINARY COMPOUNDS OF TWO NONMETALS (Given formula, write name)
Do Not use the prefix “mono” for the 1st elementUse the prefixes (1-10) and end in IDE
N2O = Dinitrogen Monoxide NO2 = Nitrogen Dioxide
NUMBER PREFIX
ONE MONO
TWO DI
THREE TRI
FOUR TETRA
FIVE PENTA
SIX HEXA
SEVEN HEPTA
EIGHT OCTA
NINE NONA
TEN DECA
BONDING
IONIC MOLECULAR COVALENT BOND
Metal & Non-Metal Non – Metal & Non-Metal
1, Name the 1st element 1. Do not use Roman Numerals2. Make the 2nd element = IDE 2. Use Prefixes ( Mono, Di, Tri)3. Use Roman Numerals ( I, II, III) 3. 2nd element ALWAYS has if Transition Element (3-12) PREFIX & IDE4. Reduce to lowest terms 4. Do Not Reduce
METALLIC COVALENT IONIC
WEAKEST STRONGER STRONGER
GOOD CONDUCTOR AS SOLID OR
SOLUTION
POOR CONDUCTOR ASSOLID OR SOLUTION
POOR CONDUCTORS AS
SOLID GOOD AS SOLUTION
MALLEABLE DUCTILE BRITTLE HARD BRITTLE
LOW MELTING POINT HIGH MELTING POINT HIGH MELTING POINT
LOW BOILING POINT HIGH BOILING POINT HIGH BOILING POINT
“SEA OF ELECTRONS”
Nae
e
e
ee
e
e
e
e
e
Na
e
e
eee
e
e
e
e
e
Nae
e
e
eee
e
ee
e
e
Ne
e
e
e
e
e
e
e
e
Sodium Nitride
Na3N
Formulas are created by the “CROSS-OVER” Method
Sodium Nitride =
Na
Sodium (Na) & Nitrogen (N)
N+ 3-
Na3N
Transition Metals Groups (3-12) & The Ions They Form
Iron = Fe3+CationCation
Chlorine = Cl -AnionAnion
Fe 3 Cl -+
Iron (III) Chloride = Fe Cl3
Pb2 +
F -Lead (Pb) & Flourine (F)
Lead (II) Fluoride = Pb F2
NUMBER ROMAN NUMERAL
ONE I
TWO II
THREE III
FOUR IV
FIVE V
SIX VI
SEVEN VII
EIGHT VIII
NINE IX
TEN X
Obey the Octet Rule 8 electrons in the valence shell is stable
Hydrogen has 1 valence electron
Oxygen has 6 valence electrons
Hydrogen has 1 valence electron
HH22OO
Dihydrogen Monoxide =
Moles & the Mole Concept
Stoichiometry
Percent (%) Composition
Molecular & Empirical Formulas
Balancing Chemical Equations
Types of Reactions
Moles & #’s of Particles
Moles
# of
Atoms Particles Molecules
Multiply by 6.02 x 1023
Divide by 6.02 x 1023
Moles & Grams
Moles Grams
Multiply by Molar Mass*
Divide by Molar Mass
* From Atomic Mass on Periodic Table
Moles # of Particles, Atoms, Molecules
Use Avogadro’s # 6.02 x 1023
Moles Grams
Use Molar Mass from Periodic Table
General Plan for Converting
Mass, Amount & # of Particles
Using Equations to make a recipe for a Ham & Cheese Sandwich
2 slices Bread + 2 slices Ham + 1 slice cheese + 1 leaf Lettuce =
1 Ham & Cheese Sandwich
A ratio of : 2 : 2 : 1 : 1 Balanced Equation
In order to feed 20 people Ham & Cheese Sandwiches you need ?
40 slices Bread 40 slices Ham 20 slices Cheese 20 leaves Lettuce
2Bd (s) + 2Hm (s) + 1Ch (s) + 1Lt (s) Bd2 Hm2ChLt (s)
Bread + Ham + Cheese + Lettuce Sandwich
Reactants Product
Making a sandwich is analogous to a chemical reaction
A “Recipe” that calls for: a ratio of specific ingredients
Molar Mass of Element
Total Molar Mass
X 100 = %%
HH22OOMass of H2 = 2 + Mass of O = 16 …….. Total Molar Mass = 18
2/18 = .111 x 100 = 11.1 % H11.1 % H
16/18 = .888 x 100 = 88.8 % O88.8 % O
Empirical Molecular
Cannot Be Reduced
CanBe Reduced
Na2 SO3 S2Cl2
SCl
REACTANTS PRODUCTS
C3H4 O2 CO2 H2O+
C3H4 O2+ 4444 CO2 H2O33
+
+22
A + B C = Combination/Synthesis
A +O2 AO = Combustion
A CO2 +H2O = Decomposition
A +BC AC +B = Single Replacement
AB +CD AD +BC = Double Replacement
CO2
H2
O2
Extinguishes Flame
Causes Explosion
Reignites Flame
Nuclear Particles
Types of Decay
Radioactive Half-Life
Name Symbol in Equations
Greek Symbol
Penetration Power
Alpha Particle + 4
+2
α Stopped by skin or a piece of paper
Beta Particle (electron)
0-1
β- Stopped by a few sheets of aluminum foil
Gamma Radiation
0 0
γ Stopped by several centimeters of lead
Neutron 1 0
Stopped by a few centimeters of lead
Positron (electron’s
antiparticle)
0+1
β+ Stopped by a few sheets of aluminum foil
He
e
γ
n n
e
Alpha Decay
+ 4
+ 2
He= = Sum of the Mass # = Sum of the Mass #
Beta Decay
= 0
-1e = On right side, increase Atomic # by 1
Mass # remains the same
Electron Capture
= 0
-1e =
On left side, Mass # is same Atomic # decreases by 1
Positron Emission
0
+1
e == On right side, Mass # is same Atomic # decreases by 1
Types of Decay
Site of Reaction
Particle When it Happens
What Happens
Alpha Right + 4+ 2
Too Many Neutrons
Mass # - 4Atomic # - 2
Beta Right 0-1
Too ManyNeutrons
Atomic # + 1
PositronEmission
Right 0+1
Too Few Neutrons
Atomic # - 1
ElectronCapture
Left 0-1
Too Few Neutrons
Atomic # - 1
He
e
e
e
One Half Life
Two Half Lives
Three Half Lives
Four Half Lives
50% or 1/2
25% or 1/4
12.5% or 1/8 6.25% or 1/16
Half–Life = Amount of time it takes for ½ of material to decay
Half–Life is a constant value unaffected by external conditions
Standard Conditions
Pressure Conversions
Gas Laws
Boyle’s Law
Charles’s Law
Gay-Lussac’s Law
Combined Gas Law
Ideal Gas Law
TemperatureTemperature
0.00 0CCelsius
273 KKelvin
O + 273=Kelvin
PressurePressure
1.00 atm
760 mmHg
101.325 kPa
101,325 Pa
kPa101.325
atm1.00
mmHg760
X 101.325 X 760
÷ 101.325 ÷ 760
Boyle’s Law = P1 × V1 = P2 × V2 (PV = K)(Inverse)
Charles’s Law = V1 V2
T1 T2
= (V K )T
=
P1 P2
T1 T2
=
(Direct)
Gay-Lussac’s Law (Direct)
= (P K )T
=
Avogadro’s Law
V1 V2
n1 n2
= (V/n = K)
Dalton’s Law Partial Pressure
=
= P1 + P2 + P3 + Pn = P Total
When Pressure increases P
Then Volume decreases V
P1 =P2 V2
V1V1 =
P2 V2
P1
V2 =P1V1
P2P2 =
P1 V1
V2
When Volume Increases V
Then Temperature Increases T
V1 =V2 T1
T2V2 =
V1 T2
T1
T2 =V2 T1
V1T1 =
V1 T2
V2
When Pressure Increases P
Then Temperature Increases T
P1 =P2 T1
T2P2 =
P1 T2
P1
T2 =P2 T1
P1T1 =
P1 T2
P2
P1 V1=
P2 V2
T1 T2
Peas (P) & Vegetables (V) on the Table (T)
PV = nRT
P = the pressure of a sample of gas
V = the volume of a sample of gas
n = the number of moles of a gas present
T = the Kelvin temperature of the gas
R = the ideal gas constant, which combinesstandard conditions & molar volume into a single constant
Thermochemistry
Thermochemical Formulas
Phase Changes
Energy
Thermochemical Equations
The amount of heat energy to raise temperature
( a quantity of energy ) = “ Joules”
q = Specific Heat Capacity in joules
m = Mass in grams or moles
∆T = Change in temperature
If the problem involves mass (m) then use specific heat capacity. If the problem involves the # of moles (n) then use the molar heat capacity
*
q = Cp (m) (∆T)
q = Cp (n) (∆T)or
m =q
Cp (∆T)=
q
Cp (m)(∆T)
&
Tem
pera
ture
(0C
)
Solid
00
Ice
FusionFreezing
1000
Liqu
idWat
er
Condensation
Vaporization
GasSt
eam
Time
All forms of energy can be divided into two categories
Kinetic Energy (KE) = Energy of Motion
Potential Energy (PE) =Result of the Attractions & Repulsion between objects
KE Energy in Action Energy of Motion
PE Stored Energy Energy of Position
Tem
pera
ture
(0C
)
Solid
00
Fusion
PE + KE =
1000
Liqu
id
Vaporization
GasPE
=
KE +PE + KE =
PE =
KE
+
PE =
KE +
EXOTHERMIC REACTIONS ENDOTHERMIC REACTIONS
Heat is released Heat is absorbed
Enthalpy ( heat ) of the products is less than that of the reactants
Enthalpy (heat) of the products is greater thanthat of the reactants
H= Hprod. – Hreactant H 0 (negative)
H= Hprod. – Hreactant H 0 (positive)
Favorable reaction – nature prefers lower energy
Unfavorable reaction
Products are more stable Reactants are more stable
Energy term is on products side of equationC(s)+ 02 (g) CO2(g) + 393.5 kJ
A + B C + HEAT
Energy term is on the reactants side of equationN2(g) + 2 02(g) + 66.2 kJ 2 NO2 (g)
X + Y + HEAT Z
H
Reactants
ProductsFinal enthalpy
Initial enthalpy
Heat absorbed∆ H
(positive)
H
Reactants
ProductsFinal enthalpy
Initial enthalpy
∆ H (negative)
Heat Released (lost)
Solutions
Concentration
Molarity
Dilution
SolutionsSolutions
Homogeneous mixtures that are made up of only one phase and are physically combined
Unsaturated Unsaturated A solution that can still dissolve more solute
SolventSolvent
The part of the solution
that gets dissolved
SoluteSolute
The part of the solution that
does the dissolving
SaturatedSaturated….has reached max. amount of solute
SupersaturatedSupersaturated....holds > than max.amount of solute
(M) Molarity =# of moles of solute
# of liters of solutionor
mol
Liters
# of Liters =mol
M
# of moles = (M) ( # of Liters)
Mass of a Solute = M x L = mol x molar mass = Mass in (g)
Divide by # of grams from Molar Mass on Periodic Table
Divide by 1000 to convert ML to L
moles grams
ML Liters
(x) Multiply by molar mass
(÷) Divide by molar mass
# of ml (÷) 1000
# of ml (x) 1000
M = Molarity V = VolumeMolarity1 x Volume1 = moles solute = Molarity2 x Volume2
M1 x V1 = M2 x V2
M1 =M2V2
V1
M2 =M1V1
V2
V1 =M2V2
M1
V2 =M1V1
M2
Naming Acids & Bases
pH
Titration
Using Polyatomic Ions & convert the suffix*
ATE IC = H2SO4 = Sulfuric Acid
ITE Ous =H2SO3 = Sulfurous Acid
ACIDS ACIDS BASESBASESBEGIN W/ A HYDROGEN ATOM
H2SHydrosulfuric Acid
END IN (OH)KOH
Potassium Hydroxide
TASTE SOUR TASTE BITTER
TURN LITMUS PAPER “RED” TURN LITMUS PAPER “BLUE”
DESTROY CHEMICAL PROPERTIES OF BASES
DESTROY CHEMICAL PROPERTIES OF ACIDS
pH of H (ACID) < 7 pH of OH (BASE) >7
pH = Negative logarithm of the hydrogen ion concentration
pH = -LOG(H+)
Concentration of Acid (H+) = Concentration of Base (OH)
MA x VA = MB x VBMA = Molarity of the Acid
VA = Volume of the Acid
MB = Molarity of the Base
VB = Volume of the Base
MA =MBVB
VA
MB =MAVA
VB
VA =MBVB
MA
VB =MAVA
MB
Cosmetics
Chemical Warfare
Forensic Science
Food Additives & Preservatives
Global Warming
Heavy Metal Poisons
Cawley, J.F., Foley, T.E., & Miller, J. (2003) Science and Students with Mild Disabilities: Principles of Universal Design. Intervention in School and Clinic, 38, 3, 160-171.
Holt ChemFile. Mini-Guide to Problem Solving.Holt, Rinehart and Winston. Austin: Texas.
Mascetta, J.A., (1996) Chemistry the Easy Way. Barrons Educational Services. Hauppauge:New York
McCleery, J.A., & Tindal G.A. (1999) Teaching the Scientific Method to At-Risk Students and Students with Learning Disabilities Through
Concept Anchoring and Explicit Instruction. Remedial And Special Education, 20, 1, 7-18.
Orkwis, R. (1999) Curriculum Access and Universal Design, Reston,VA: Council for Exceptional Children