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