final exam helpful hints, charts, tables, diagrams metric
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FINAL EXAM Helpful Hints, Charts, Tables, Diagrams
Metric Conversions
The - - - Great - - - Monarch- - - King - Henry - Died - by - Drinking - Chocolate - Milk- - - Made- - - Near- - - Poland Scientific Notation - Use exponent key!
Significant Figures
You may want to use this diagram to help determine the number of significant figures in a measured value…
Pacific Atlantic
If the decimal point is present, start counting digits from the Pacific (left) side, starting with the first non-zero
digit. Ex. 0.003100 (4 sig. figs.)
If the decimal point is absent, start counting digits from the Atlantic (right) side, starting with the first non-zero
digit. Ex. 31,400 (3 sig. figs.)
1. All non-zero digits are significant.
2. All zeros between two other digits are significant.
3. All zeros to the right of the decimal and at the end of the number are significant
4. All other zeros are NOT significant and serve as placeholders.
Matter Flow Chart
Chemical change(new compounds/elements formed) vs. Physical change(same compound/element after change)
Signs of a Chemical Change (Reaction)
Table Comparing Solids, Liquids, Gases
State Volume/Form/Shape
Compressibility
Arrangement &
Closeness of
Particles
Motion of
Particles
Attraction
between
Particles
Boiling Point
Gas No definite volume/form/shape
Compressible
Random & far apart Fast
Diffusion
Fluid
Little to none Lower than room
temperature
Liquid Has a definite volume
No definite form or shape
Non-compressible
Random & close Moderate
Fluid
Moderate Higher than room
temperature
Solid Definite volume, form and
shape.
Incompressible
Definite & close Slow
Vibration
Strong Much higher than
room temperature
Metals vs. Nonmetals
Metals Malleable,
Ductile
All solid EXCEPT
Hg
Lustrous Conduct Heat and
Electricity
Low I.E. and E.N
Form (+)ions
Nonmetals Brittle Solids Can be solid, liquid or
gas at room
temperature
Dull Good Insulators –
do not conduct
High I.E. and E.N
Form (-) ions
Share electrons
with other
Nonmetals
Model of the Atom - location of the proton, electron and neutron
Dalton Thompson Millikan Rutherford Bohr Quantum
Experiment
Experiment on mixtures of gasses
Cathode Ray Tubes
Oil Drop Experiment
Gold Foil Experiment
Element Emission Spectra
Quantum or Wave Mechanical Model
Dalton’s Atomic Theory
Charged particles in the atom
Electrons in
fixed orbits
Model of atom Solid Sphere Plum Pudding Model
Calculated the charge and mass of electron
Nuclear Model
Nucleus: • small • dense • + charged Most of atom is empty space
Plantary Model
Electrons gain
and lose
energy in fixed
amounts called
QUANTA
Orbitals - electron clouds that overlay with each additional energy level
Rules for Isotopes
1. The number of protons in the nucleus of an atom is equal to the atomic number (Z).
2. In a neutral atom, the number of electrons is equal to the number of protons.
3. The mass number (A) of an atom is equal to the sum of the
number of protons and neutrons in the nucleus.
4. The number of neutrons is equal to the difference between the mass number (A)and the atomic number (Z).
Rules for Ions
1. Cation – the number of electrons = number of protons – the absolute value of the charge.
Ca 2+
: #e’s = 20 – 2 = 18 2. Anion – the number of electrons = number of protons + the absolute value of the charge.
O2-
: #e’s = 8 + 2 = 10
Nuclear chemistry
Radioactive Particles: alpha, beta, gamma
Penetrating Ability Behavior in Electric Field
Alpha Decay : Beta & Gamma Decay :
Half Life 500 g 250 g 125 g 62.5 g 31.25 g 15.625 g 7.8125 g
Initial Mass represents 1 half life Final mass after 6 half lives
Electron Structure- Apply Quantum Model
The electron arrangement in the atom determines how the atom will react and the properties it will display
• Use the Diagonal Rule to follow sequence of electron orbitals, sublevels, and energy levels
Orbital Sequence:1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, and 7p
s,p,d,f - ‘some poor dumb fool’
Chlorine –
Orbital notation 1s_____2s_____2p_____ _____ _____3s_____3p_____ _____ _____
Electron configuration: 1s2, 2s2, 2p6, 3s2, 3p5
Noble Gas Configuration: [Ne] 3s2, 3p5
Table Comparing - Ionic Compounds, Covalent Compounds, Metallic Compounds
Substance Bonding Properties
Ionic Electron Transfer to form + and – ions
Electrostatic Attraction
Will always bond a Metal & NonMetal
(or Cation & Anion)
Hard but brittle
High melting and boiling points
Soluble in water(polar solvent)
Conduct electricity when molten or in
aqueous(water) solution
Use “SWAP & DROP” to write formulas
Covalent(Molecular) Electrons are shared between 2 bonding atoms
- Non-Polar covalent - e-’s shared equally
- Polar covalent - e-’s NOT shared equally
Will always bond 2 NonMetals
Soft
Low melting and boiling points
Not soluble in water. Is soluble in non-polar
solvent (oil)
Do not conduct electricity (insulators)
Use prefixes to name - mono-, di-,... DO
NOT SWAP AND DROP
Metallic
Delocalized “sea” of electrons
Electrons are mobile within the metal
Hard yet malleable
Ductile
Lustrous
High melting and boiling points
Conducts both heat and electricity
Draw the Lewis Structure
1. Write the formula
2. Count the valence electrons for each atom in the formula. Add these electrons together to determine the # of
ELECTRONS AVAILABLE
3. Find the central atom. If carbon is present, choose carbon.
Choose the element that is present in smallest number
Ex. H2O there is only 1 oxygen. Choose oxygen as the central atom
4. Share 2 electron between each atom. All atoms EXCEPT hydrogen must have 8 dots after bonding, 2 per
side.
Hydrogen has only 2 after bonding
5. Count the ELECTRONS USED. If the electrons used = electrons available, you are finished.
6. If the # of electrons used is greater than the # of electrons available by 2, redraw the dot structure and include
a double bond on the central atom.
7. If the electrons used is greater than the electrons available by 4, redraw the dot structure and include a triple
bond ( or 2 double bonds around the atom.
VSEPR - electron clouds repel one another resulting in different molecular shapes (geometry)
Intermolecular Forces – in molecular compounds
Mole Calculations
Mass # of
particles
molar
mole mass mole 6.02 x 1023
MOLE HILL
# Moles
(x or ÷ Molar Mass) (x or ÷ 6.02 x 1023
)
Mass in grams # Particles
Nomenclature:
All transition metals have more than 1 oxidation number (charge!) EXCEPT Ag : +1 charge and Zn : +2 charge
Covalents: write first nonmetal name with prefix if
there is a subscript, write second nonmetal name
always with prefix and ide ending.
Acids: KNOW: hydrochloric acid, sulfuric acid,
phosphoric acid, nitric acid, acetic acid, carbonic acid
Ionics: write metal name then either nonmetal name
with ide ending or polyatomic ion name. Decide if
metal needs a Roman numeral
Common Names: Water, Ammonia, Methane
Diatomic Elements: H2, O2, N2, Cl2, Br2, I2, F2
Percent Composition is an analysis of a
chemical’s content using masses. Here is how
it is calculated.
% Comp. = mass element x 100
mass of compound
Atomic mass on PT can be used.
% Comp. = atomic mass element x 100
Molar mass of compound
Empirical Formula 1. Cross out % and make grams if given %
2. Convert grams to moles for each element
3. Divide each moles answer by the smallest
4. The whole numbers obtained in step 3 are your
subscripts. If a .5 number is obtained in step 3
multiply all answers by 2.
Molecular Formula
1. You must have the empirical formula first.
2. Divide the mass given in the problem by the
molar mass of the empirical formula.
3. Use the whole number answer from number 3 to
multiply the subscripts.
CHEMICAL REACTIONS
Combustion Hydrocarbon + O2 CO2 + H2O
Potential Energy Diagram
STOICHIOMETRY GENERAL SET UP
Vertical Agreement Method: Use the COEFFICIENTS in the balanced eqn to set up a proportion to solve for ‘X’
1. Balance the equation.
2. Set up a proportion – Steps 3 - 7
3. Put the “given” quantity over the correct chemical with the proper unit.
4. Put an X over the “asked for” chemical with the proper unit.
5. ALWAYS put the coefficients of the “given” and “asked for” under the correct chemical.
6. If the quantity is moles do nothing else.
7. If the quantity is mass find the molar mass of the chemical and multiply it by the coefficient.
8. (If the quantity is volume multiply the molar coefficient by 22.4L
9. Set up the ratios and solve for X.
GENERAL FORMAT – SET UP RATIO
Number Unit Formula(of the ‘Given’) = ‘X’ Unit Formula(of the ‘Asked For’)
(Coefficient for the ‘Given’)(Factor) (Coefficient for the ‘Asked for’) (Factor)
If the Unit is then use (Factor)
________________________________________________________________________
Moles ( 1 )
Mass(g) (molar mass)
Particles(atoms, ions, molecules) (6.02 x 10 23
)
Liters of gas at STP ( 22.4 L)
Heating Curve
Melting point = 40oC Boiling point = 110
oC
Table Comparing Heat values and Phase Changes
Complete the table – refer to the heating curve below
Section Process Temperature
Change
K.E. or P.E Heat, q, Equation
AB Warming the Solid Yes K.E. q = m Cp(solid) ∆T
BC Phase change - Melting No P.E. q = mHf
CD Warming the Liquid Yes K.E. q = m Cp(liquid) ∆T
DE Phase change - Melting No P.E. q = mHv
EF Warming the Gas Yes K.E. q = m Cp(gas) ∆T
Gas Law Graphs- Direct and Inverse Relationships
Pressure/Temperature(at const V) Pressure/Volume(at const T) Volume/Temperature(at const P)
Combined Gas Law
P1V1 = P2V2
T1 T2
P1 = Initial pressure P2 = new pressure
V1 = Initial volume V2= new volume
T1 = Initial temperature in K T2 = new temperature
Use this formula for changing conditions. Look for words that mean change – increase, decrease, rise, lowers new,
original
Temperature must be in Kelvin K = ° C + 273 Ideal Gas Law
PV = nRT P = pressure(must be in atm)
V = volume (must be in L)
n = moles (may need to convert grams to moles)
R = universal gas constant = 0.0821 if pressure is in atm
T = temperature (must be in Kelvin) Dalton’s Law of Partial Pressure
Ptotal = P1 + P2 + P Patmospheric = Pdry gas + PH2O Vapor
P1, P2, and P3 = the pressure of each individual gas and must have the same units PH2O Vapor= pressure of water vapor left behind during water displacement. It depends on the temperature
Solutions
Molarity = Moles Solute moles
Liter of Solution
M L
• The solute must be converted to moles using the molar mass of the periodic table
• The volume of solution or solvent must be in liters. Use “King Henry…” (KHDBdcm) to complete the metric
conversion
• Molarity is abbreviated with a capital M
Dilution: M1 x V1 = M2 x V2
Colligative properties a - properties of a solvent that are changed when a solute is added, and depend ONLY on the
number (moles) of particles that are present. They include boiling point elevation, vapor pressure lowering
and freezing point depression.
Nonelectrolytes are solutes that DO NOT break apart into ions. The number of particles that can be obtained from
an electrolyte (an ionic solute) can be determined by adding up the subscripts in the formula.
Acids and Bases
pH SCALE:
• Measure of the hydronium ion in solution.
• Allows us to get rid of exponent numbers
• Goes form 0�14, with pH = 7 being a neutral solution
pH
•••• pH = -log [H3O+] Use the Calculator!!
pOH
•••• pOH = -log [OH-] Use the Calculator!!
pH + pOH = 14 and Kw = [H3O+] x [OH-] = 1 x 10-14
TITRATIONS:
• A laboratory technique to determine the
molarity of an unknown acid or base – neutralization reaction
MaVa = MbVb
CHEMICAL EQUILIBRIA Equilibrium Constant, Keq – For the reaction:
wA + xB yC + zD
Keq = [C]y[D]
z
[A]w[B]
x
NEVER include SOLIDS (s) OR LIQUIDS (l) in the Keq Expression
ONLY GASES (g) and AQUEOUS (aq)
Le Chatelier’s Principle
Laboratory • 4 Ways to Increase the Rate(speed) of Reaction
• List as many words as possible that indicate a chemical change. Ex. tarnish
• List as many words as possible that indicate a physical change. Ex. sublime
• Lab Equipment - Balance, Beaker, Graduated Cylinder, Erlenmeyer flask, Bunsen burner, Crucible
• Safety rules
• Tests for Gases - CO2, O2, and H2