Naming Compounds Ionic Compounds Covalent Compounds Acids

Look at the first element. Is it a metal, nonmetal, or hydrogen? Metal = Ionic Bond Nonmetal = Covalent Bond Hydrogen = Acid

Ionic Compounds Writing Formulas (Binary) Binary Compounds have only two types of elements Determine the ions’ charges using the periodic table or compound’s name. Balance charges in the compound.

Ionic Bonds – Naming Binary Compounds Check to see if the element has more than one oxidation number. If the metal has more than one oxidation number, the compound will be named using the Cation - Roman Numeral – Anion The anion’s ending is changed to ide for all binary compounds.

Ionic Compounds with Polyatomic Ions Ionic compounds that contain more than two types of atoms are called polyatomic. Examples of Polyatomic Ions Sulfate – SO4-2 Carbonate – CO3-2 Phosphate – PO4-3 Ammonium – NH4+

Polyatomic Ions Cont. These compounds are named in three ways: Polyatomic Ion – Polyatomic Ion Ex. Ex. (NH4)3PO4 Ammonium Carbonate Cation – Polyatomic Ion Ex. Lithium Nitrate Ex. Ca(NO3)2 Polyatomic Ion – Anion (with ide ending) Ex. Ammonium nitride

Covalent Compounds To name covalent compounds: prefix-first element prefix-root of second element - ide Prefixes 1 = mono 6=hexa 2 = di 7=hepta 3=tri 8=octa 4=tetra 9=nona 5=penta 10=deca

Naming Acids Does the acid contain oxygen? YES Oxyacid Change polyatomic ending from: ate to ic ite to ous Add the word Acid NO Binary Acid Hydro-root of nonmetal - ic Add the word Acid

If water molecules are attached= Hydrate Add numerical prefix and the word hydrate Ex. MgSO4 • 7H2O magnesium sulfate pentahydrate

Chemical Bonds Ionic Bonding Covalent Bonding Acids

Ionic Bonding Positively charged ions are attracted to negatively charged ions, making a neutral compound.

The Octet Rule Atoms tend to gain or lose electrons in order to acquire a full set of valence electrons. Therefore, atoms will transfer electrons to each other in order to have a full set of valence electrons. When electrons are transferred, ionic bonds are formed. Ionic Bonding

Energy Changes in Bond Formation Energy is absorbed when an element loses an electron. Energy is released when an element gains an electron. Lattice energy is the energy released when ionic bonds are formed.

Properties of Ionic Compounds high melting points dissolve in water: which makes solutions good conductors of electricity have large electronegativity difference between elements usually form between metals and nonmetals Lattice crystal: the regular pattern in which a crystal is arranged.

Types of Ions 1) Monoatomic Ions - have one element 2) Polyatomic Ions - consist of more than one atom and have an overall charge Atoms in polyatomic ions are held together by covalent bonds. Ex. Sulfate ion, ammonium ion, etc. See polyatomic sheet

Covalent Bonding Covalent Bonds are formed by SHARING pairs of electrons between 2 atoms. Usually formed between two nonmetals Molecules a group of atoms held together by covalent bonds molecular substance - contains molecules

Types of formulas for covalent bonding Molecular formula - tells you how many atoms make up a compound ex. C6H12O6 H2O Structural formula - shows how the atoms are bonded to each other

Multiple Bonds Single Covalent Bonds -share one pair of electrons Double bonds - share 2 pairs of electrons Triple Bonds - share 3 pairs of electrons (STRONGEST BOND) Use dashes to represent covalent bonds in a structural formula.

:N = N:

Exceptions to the Octet Rule Atoms with less than an octet Boron BF3 Atoms with more than an octet Phosphorus and Sulfur PCl5 Molecules with an odd number of electrons ex. NO

Properties of Covalent Bonds -Low melting points, brittle, strong odor, poor conductors of electricity Shared electrons are attracted to more electronegative element Polar bonds - form between elements with big differences in electronegativity ex. H2O Nonpolar bonds - exert equal pull on electrons ex. F-F or O=O

How can you tell if a compound has ionic or covalent bonds? Use electronegativity difference between the elements non polar covalent less than 0.4 polar covalent 0.5 - 1.9 ionic bonds greater than 2.0 See electronegativity chart for values.

Acids A molecular compound that dissolves in water to produce hydrogen ions and a characteristic ion. In water, acids behave like ionic compounds

Types of Acids Organic Acids contain the carboxylic group, -COOH. Binary Acids: contain hydrogen and another element Oxo Acids: contains oxygen and another element