Chemistry Review for Final Exam

Isomers

Same molecular formula, different structureDraw 2 isomers with the formula C4 H10

Bonds

Octet RuleIonic : metal & nonmetal; electrons

transferredCovalent: 2 non-metals; electrons are shared

Single Double Triple

Electron Configuration

Maps the location of the electrons around the nucleus

1s2 2s2 2p6 3s1 Which element?What’s the valence shell?Which energy level is completely full of

electrons?

Electron Configuration

Aufbau Principle Lowest energy levels fill first

Pauli Exclusion Principle 2 electrons in the same energy level have separate

spinsHund’s Rule

In energy levels with multiple orbitals, one electron goes in each orbital FIRST then additional ones (up to 2 in an orbital) are added

Draw the Aufbau diagram for carbon

3s2p

2s1s

Periodic Table Trends

IE: Ionization energy-the amount of energy needed to take an electron from an atom increase across decrease down

AS (Atomic Size) decrease across because of shielding increase down

EN (Electronegativity-the ability of an atom to take an electron from another. ) Higher in non metals Increase across decrease down

The Mole

The mole highway!

How many moles are in 3.4g of LiCl?

How many liters are in 58g of steam (H2O)?

Chemical and Physical Changes

Chemical change: results in a rearrangement or a recombination of atoms, different from the reactants. Cooking an egg Burning wood Baking a cake

Physical change: atoms have not been rearranged Boiling water Tearing paper Breaking glass Dissolving sugar in water

Endothermic and Exothermic

Endothermic: heat is absorbed by the system An egg absorbs heat as it cooks A scoop of ice cream absorbs heat as it melts An ice cube melts

Exothermic: heat is released Nuclear fission Nuclear fusion A fire in the fireplace

Energy curves…

Kinetic Molecular Theory

Matter is made of molecules.The molecules are in constant motionMolecules move faster, bump into each other

more often if energy is added (aka, if temperature is raised)

This is a theory because it explains what happens with molecules…its not a summary.

Nuclear Fission & Fusion

Fission: the splitting of an atom when it’s bombarded with a small particle, like a neutron. Releases a great amount of energy.

Fusion: the combining of atoms to form heavier ones. Releases more energy than fission. Occurs in the core of stars. Thought to occur after the Big Bang to make the elements in the stars.

Radiation

Ionizing and non-ionizingIonizing: more dangerous. UV rays are

ionizing. Ionizing strips electrons from atoms, causing them to be ionized…these ions are called free radicals and may contribute to human illness like skin cancer.

Non-ionizing: the visible spectrum and the long wavelengths of radiowaves and infrared waves. Produce heat, but does not ionize atoms.

Visible Spectrum

ROYGBIVWavelength

Long = red Short = violet

Frequency Low = red High = Violet

Radiation

Alpha He Least penetrating

Beta Electron Positron

Gamma High energy Accompanied by alpha or beta particles

Nuclear Equations

Thorium-238 undergoes alpha decay. What is the final product?

When Aluminum-26 undergoes electron capture, what is the final product?

Bohr Model

The energy levels are represented as rings around the nucleus. We use it to teach because its easy to understand, but it’s not the accepted model…the Schroedinger model of the atom (the electron cloud model) is the accepted model.

Arrangement of the Periodic Table

MetalsNonmetalsMetalloidsAlkali metalsAlkali earth metalsHalogensNoble GasesPeriodsFamilies

Naming Ionic Compounds

Name the metal, name the non-metal. Add an –ide ending on the nonmetal!

Li2O

CaCl2

Naming Ionic Compounds with a polyatomic Ion

Name the metal, name the poly!

Mg(OH)2

Li3 PO4

Name ionic compounds with a metal that can have more than one charge

1.) determine the charge of the anion2.) the charge of the metal must be equal and

opposite that of the anion.3.) write the charge of the cation as a roman

numeral after the name.SnOMnPPbCl

REDOX

LiCl + K KCl + Li

Li+ + e- LiK K+ + e-

Intermolecular Forces

Dipole-Dipole A dipole is a molecule with a permenant division of charge (+) end of one molecule is attracted to the (-) end of

anotherDispersion

Happens in non-polar molecules Caused by electrons “bunching up” on one side of the

molecule for a moment…making that side of the molecule negatively charged for just an instant

Hydrogen Bond Strongest! Takes the most energy to break. Hydrogen on one molecule is attracted to the lone pair of

electrons on a neighboring molecule.

Intramolecular Bonds / Forces (within the same molecule)

Ionic Electrostatic force Cation & anion Electrons are transferred

Covalent 2 non-metals Electrons are shared

Metallic Electron Sea Swimming valence electrons are attracted to the

positive nucleus on a neighbor Explains properties of metals (malleable, conductors)

Parts of an atom

Nucleus = protons and neutronsElectrons move around the nucleus

Atomic # = # of protonsMass of a proton is about 1 amu

Protons = electrons ( in a neutral atom)Mass # = protons + neutrons

How many protons, neutrons, electrons?

1.) Na p= n= e-=

2.) Na+ p= n= e-=

3.) O p= n= e-=

4.) O-2 p= n= e-=

Heisenberg Uncertainty Principle

the more you know the position of a particle, the less you know about its velocity, and the more you know about the velocity of a particle, the less you know about its instantaneous position.

Half-Life: the amount of time it takes for the mass of a radioactive substance to decrease by 1/2

How long will it take a 20g sample of Carbon-14 to decay to 2.5g?

Stoichiometry

2H2 + O2 2H2O1. If you begin with 1.2x106 moles of hydrogen, how many moles of

water will be produced?

2. If you want to make 3.56g of water, how many moles of oxygen do you need?

3. If you start with .04 moles of hydrogen how many grams of water will you produce?

Metric Conversions

1.) Convert 2.2m to nm:

2.) Convert 1.35x10 34 kilograms to grams:

3.) Change 4.5x1023 milliseconds to hectoseconds:

The Big Bang (see the last page of the study guide)

Explains how hydrogen atoms formedExplains how hydrogen and helium formed

other, heavier elementsExplains the role of the four fundamental

forces in the creation of atoms

Atoms, molecules, ions, isotopes

Atom Basic unit of matter with a dense central nucleus and

electrons that move around the outside. Neutral charge

Molecule Made of atoms bonded together

Ion An atom that has lost or gained electrons and has a charge Cations, anions

Isotope Atoms of the same element that differ in the number of

neutrons Have different atomic masses

Moles and molar mass

1 mole of a compound = the molar mass of the compound, in grams

1 mole of C6H12O6 = 180gHow much does 1 mole of CO2 weigh?

Naming covalent compounds

Name the first element normally If there is only one of the first element, don’t use a prefix Use a prefix if there is more than one of the first element

Name the second element by using a prefix and replacing the ending with –ide.

COCO2

SO3

P5F7

Predicting Products

First you need to know what kind of reaction you’re dealing with:

Combo: A + B ABDecomposition: AB A + BSingle replacement: AB + C CB + ADouble replacement: AB + CD CB + ADCombustion: hydrocarbon + O2 CO2 + H2

O

Predicting Products

Combo: A + B AB Decomposition: AB A + B Single replacement: AB + C CB + A Double replacement: AB + CD CB + AD Combustion: hydrocarbon + O2 CO2 + H2 O

Predict the products of the following reactions:K + AgCl

CH4 + O2

MgO + CaPO4

Balancing Equations

C2H10 + O2 CO2 + H2O

AgCl + Li LiCl + Ag

Na + O2 Na2O

How is different colored light produced when an electric current is passed through a tube full of a

gas?

Electrons in the gas atoms are energized and bump up to higher energy levels. As they fall back to their ground state they emit energy in the form of light. The more energy they lose, the more energetic the light they emit.

Mole conversions

How many atoms of gold are in 629 moles of gold?

How many atoms are in 629 moles of CO2

How many molecules are in 629 moles of CO2

Electron Dot Diagrams

Draw the EDD for an atom of helium:

Draw the EDD for an atom of calcium:

Draw the EDD for NaCl

Draw the EDD for CO2

Stability of isotopes

Macroscopic & Submicroscopic (molecular) views of matter