What will be on the test on 10-30? Chapters 4,5 and 7 Note: You will be given a periodic table and copy of conversions page from the back of the book. You need to bring a green scantron and you are allowed ½ sheet of paper on which you can write equations, etc.

1. Naming Covalent Compounds See Study Assignment from Lab 2 1. Naming Covalent Compounds See Study Assignment from Lab 2. Lewis Dot structures: See Study Assignment from Lab See also: Resonance and exceptions to the octet rule Must obey the Octet Rule: the tendency for atoms to seek 8 electrons in their outer shells Must have the correct number of valence electrons around each atom in the molecule. Halogens Like to be terminal Like to have one single bond and 3 lone pairs (non-bonding electrons) Carbon Likes to have 4 single bonds and no lone pairs A double bond counts as two singles A triple bond counts as three singles Likes to be central Likes to bond to other carbons

2. Lewis Dot structures: Silicon Likes to do what carbon does Oxygen Likes to have two single bonds and 2 lone pairs Sulfur Likes to do what oxygen does, but may expand its octet Nitrogen Likes to have 3 single bonds and one lone pair Phosphorus Likes to do what nitrogen does, but may expand its octet Hydrogen Likes to be terminal with only one single bond No lone pairs! Boron Likes 3 bonds and no lone pairs (sextet-exception to the octet rule)

2. VSEPR Opposite charges attract while like charges repel each other. Protons and electrons attract each other, but two electrons repel each other.

Valence Shell Electron Pair Repulsion Theory VSEPR theory: Electrons repel each other Electrons arrange in a molecule themselves so as to be as far apart as possible Determines molecular geometry

This was removed due to size limits on website…

You will need the information from this table only for determining molecular geometry (similar to quiz)

3. Electronegativity The measure of the ability of an atom to attract electrons to itself Increases across period (left to right) and Decreases down group (top to bottom) fluorine is the most electronegative element francium is the least electronegative element

Non-Polar Covalent Bond: Types of Bonding ENCl = 3.0 3.0 - 3.0 = 0 Covalent Non-Polar Covalent Bond: Difference in electronegativity values of atoms is 0.0 – 0.4 Electrons in molecule are equally shared Examples: Cl2, H2, CH4 ENCl = 3.0 ENH = 2.1 3.0 – 2.1 = 0.9 Polar Covalent Polar Covalent Bond: Difference in electronegativity values of atoms is 0.4 – 2.0 Electrons in the molecule are not equally shared The atom with the higher EN value pulls the electron cloud towards itself Partial charges Examples: HCl, ClF, NO

Ionic Bond: Difference in EN above 2.0 ENCl = 3.0 ENNa = 1.0 3.0 – 0.9 = 2.1 Ionic Ionic Bond: Difference in EN above 2.0 Complete transfer of electron(s) Whole charges

Molecular Polarity (Examples)

Figure 4.5 Examples

5. Molar Mass The mass, in grams, of one mole of any element or compound Abbreviated with capital, italicized M Unit = grams/mole = g/mol Also called Formula Mass and Formula Weight

Chapter 5, continued Avogadro’s number, calculations involving molecular weight, moles to mass, etc. See Worksheet for Chapter 5 and see related problems at the end of the chapter.

5. Chemical Reactions Writing Chemical Equations A chemical equation uses chemical formulas and other symbols showing what reactants are the starting materials in a reaction and what products are formed. The reactants are written on the left. The products are written on the right. Coefficients show the number of moles of a given element or compound that react or are formed.

5. Introduction to Chemical Reactions Balancing Chemical Equations Study assignment for balancing chemical equations. Page 191 and 193. stoichiometry, % yield: Calculations using the balanced reaction See Worksheet and related problems at the end of the chapter. Limiting reagent problems will not be included until the final.

Types of reactions: Combination, Decomposition, Single Replacement, Double Replacement Combustion reaction involves the burning of a compound, usually a hydrocarbon, in oxygen to form heat, carbon dioxide and water

6. Oxidation and Reduction A. General Features Oxidation is the loss of electrons from an atom. Reduction is the gain of electrons by an atom. Both processes occur together in a single reaction called an oxidation−reduction or redox reaction. A redox reaction always has two components, one that is oxidized and one that is reduced. A redox reaction involves the transfer of electrons from one element to another.

5. Oxidation and Reduction A. General Features Zn loses 2 e− to form Zn2+, so Zn is oxidized. Cu2+ gains 2 e− to form Cu, so Cu2+ is reduced.

5. Oxidation and Reduction A. General Features Cu2+ gains 2 e− Zn + Cu2+ Zn2+ + Cu Zn loses 2 e– Each of these processes can be written as an individual half reaction: Oxidation half reaction: Zn Zn2+ + 2 e− loss of e− Reduction half reaction: Cu2+ + 2e− Cu gain of e−

5. Oxidation and Reduction Zn + Cu2+ Zn2+ + Cu oxidized reduced A compound that is oxidized while causing another compound to be reduced is called a reducing agent. Zn acts as a reducing agent because it causes Cu2+ to gain electrons and become reduced.

5. Oxidation and Reduction Zn + Cu2+ Zn2+ + Cu oxidized reduced A compound that is reduced while causing another compound to be oxidized is called an oxidizing agent. Cu2+ acts as an oxidizing agent because it causes Zn to lose electrons and become oxidized.

5.4 Oxidation and Reduction A. General Features

5, Oxidation and Reduction Examples of Oxidation–Reduction Reactions Zn + 2 MnO2 ZnO + Mn2O3

Chapter, 7 Properties of Gases Problems using the Gas Laws: See worksheet… Intermolecular Forces Properties related to melting point, boiling point Anything that is on the power point presentations can be included on the test, except for solubility section (precipitation reactions), and limiting reactant..