Chapter 6 - Nomenclature Chemical Names & Formulas

Introduction to Chemical Bonding §Two types of Bonding l Ionic Bonding - transfer of electrons l Covalent Bonding - sharing of electrons

§Bonding takes place at the highest energy level, s and p sublevels. §If there are less than half the electrons between the s and p sublevels, the atom will lose the electrons. §If there are half or more electrons between the s and p sublevels, the atom will gain electrons.

§Know the trends on the periodic table for how many electrons will be gained or lost.

Ionic Bonding §Because there is a transfer of electrons, elements will lose or gain electrons. §If an element loses or gains electrons, it will then become a charged particle - ion. l Positive ion - cation l Negative ion - anion

Cations §Substance that has lost electrons. §The charge is equal to the number of electrons that are transferred. §Ca 2+ - calcium that has transferred two electrons to another substance (anion). §Mg 2+ - magnesium that has transferred two electrons to another substance (anion).

Anion §Substance that has gained electrons. §The charge is equal to the number of electrons that are transferred. §F 1- - fluorine that has accepted one electron from another substance (cation). §O 2- - oxygen that has accepted two electrons from another substance (cation).

Ionic Bonding §Ionic bonding is the accepting or donating of electrons. §Metals are donors. §Nonmetals are acceptors. §Hence, ionic bonding will occur between metals and nonmetals.

Oxidation Numbers §Possible charges on an element. §Any single element, by itself, has a charge of zero. §An element takes on a charge when put with other elements.

Basic Rules of Oxidation Numbers §Group 1 elements are always 1+. §Group 2 elements are always 2+. §Group 17 elements will be 1-. §Group 16 elements will be 2-. §Group 15 elements will be 3-.

Writing Formulas from Ions §The total overall charge of a compound is zero. §Use subscripts to balance the charge to zero.

§Ca 2+ and S 2- l CaS §Na + andCl - l NaCl §Ba 2+ andN 3- l Ba 3 N 2

Writing Ions from Compounds §Go with what you know.

§MgCl 2 l Mg 2+ andCl - §CuBr 2 l Cu 2+ andBr - §FeCl 3 l Fe 3+ andCl -

Polyatomic Ions §Many atomed charged particle that acts as a single unit. §Polyatomic ions have specific names. Use the names. §Common polyatomic ions include: l Nitrate ____________ l Sulfate ____________ l Phosphate ____________ l Carbonate ____________ l Hydroxide ____________ l Chlorate ____________

§Ba 2+ andSO 4 2- l BaSO 4 §Na + andClO 3 - l NaClO 3 §Fe 2+ andCO 3 2- l FeCO 3

§KNO 3 l K + andNO 3 - §CoSO 4 l Co 2+ andSO 4 2- §LiClO 3 l Li + andClO 3 -

More than one of the Polyatomic Ion Needed to Balance the Charge  If more than one of the polyatomic ions is needed to balance the charge, you must use parentheses () around the ion. §Ba(NO 3 ) 2 l Ba 2+ andNO 3 -

§Mg 2+ and ClO 3 - l Mg(ClO 3 ) 2 §Fe 3+ and SO 4 2- l Fe 2 (SO 4 ) 3 §Co 3+ and NO 3 - l Co(NO 3 ) 2

Naming Ionic Compounds §Binary Ionic Compounds - Types 1 & 2 l A compound that contains a positive ion (cation) and a negative ion (anion). l Bi- means two l Positive ion is written first, negative ion is written second in a chemical formula.

Type 1 - Binary Ionic Compound §The cation of a Type 1 has only one possible charge. §Name the first element (cation) as is. §Name the second element (anion) as is with an ending of “-ide”. §Example:CaCl 2 l Calcium chloride

More Examples: §NaBr-Sodium bromide §MgO-Magnesium oxide §KBr-Potassium bromide §BaS-Barium sulfide

Type 2 - Binary Ionic Compounds §The cation has multiple charges - copper can have a charge of 1+ or 2+. §Determine which charge is being used. Use the anion as the guide. §Name the element as is. §Use a Roman numeral to indicate the charge being used.

§Name the anion as is, using an ending of “-ide” as with Type 1 compounds. §Example:CuCl 2 l Copper (II) chloride l MnO 2 -Manganese (IV) oxide l NiO-Nickel (II) oxide

Naming Type 1 & 2 with Polyatomic Ions §Form compounds called ternary compounds - compound that contains atoms of three different elements. §Polyatomic Ion - many atomed charged particle acting as a single unit. l poly - many l atomic - atom l ion - charged particle

Polyatomic Ions - few examples §N§NO3 1- -nitrate §S§SO sulfate §P§PO phosphate §C§CO carbonate §C§ClO chlorate §O§OH 1- -hydroxide

Type 1 & 2 Compounds with Polyatomic Ions §N§Name the cation using the rules for Type 1 or Type 2 compounds. §N§Name the polyatomic ion as is - use the name on the chart. §E§Examples: lNlNaNO 3 -sodium nitrate lBlBaSO 4 -barium sulfate

Name these: §LiOH-lithium hydroxide §Mg(NO 3 ) 2 -magnesium nitrate §CrCl 3 -chromium (III) chloride §Al 2 O 3 -aluminum oxide §CoBr 2 -cobalt (II) bromide §Fe 2 O 3 -iron (III) oxide

Covalent Bonding §C§Covalent bonding involves the sharing of electrons between substances. §M§Molecule - smallest neutral unit of a substance that still has the properties of the substance. §M§Molecular formula - shows the kinds of numbers of atoms present in a molecule of a compound. §O§Occurs between nonmetals and nonmetals.

§Because these are molecules and are covalently bonded, ions are not formed - there is no transferring of electrons to form ions. §Prefixes are used in naming nonmetal-nonmetal compounds.

Prefixes §mono-1 §di--2 §tri--3 §tetra--4 §penta--5 §hexa--6 §hepta--7 §octa--8 §nona--9 §deca--10

Prefixes: §Only used for nonmetal-nonmetal compounds. §Mono- is never used on the first element. §Second element always has a prefix.

Naming Molecular Compounds §Name the first element as is. If there is more than one of the first element, you must use a prefix. §Name the second element with a prefix to indicate how many atoms there are and add the ending “-ide”. §Example: l CO 2 -carbon dioxide

Name these: §N§N 2 O-dinitrogen monoxide §P§PCl 3 -phosphorus trichloride §S§SF 6 -sulfur hexafluoride §P§P 4 O 6 -tetraphosphorus hexaoxide §S§SO 2 -sulfur dioxide §N§NO 3 -nitrogen trioxide §S§SO 4 -sulfur tetraoxide

Naming Acids §When dissolved in water, certain molecules produce hydrogen ions - H+. §These substances are called acids. §An acid can be viewed as a molecule with one or more H+ ions attached to an anion. §The rules for naming acids depend on whether the anion contains oxygen.

Naming Acids §Identify the compound as being an acid - the first element is hydrogen (two exceptions are H 2 O and H 2 O 2 ) §Find the anion on the chart. §Name the anion. §Following across to the name of the acid. §Name the acid.

Naming Acids §If you move up the chart, you gain oxygen. §If you move down the chart, you lose an oxygen. §Start with what you know - usually the -ate group.

Examples: §HCl l The chloride ion (anion) is a single element and ends in “- ide”. l It is at the bottom of the chart. l Move across and the name of this acid is hydrochloric acid.

§H 3 PO 4 l The anion is phosphate. l Move across to the acids and the name of this acid is phosphoric acid. §H 2 SO 4 l The anion is sulfate. l Move across to the acids and the name of this acid is sulfuric acid.

§HClO 2 l Identified as an acid. l The anion is ClO 2 1-, which is one less oxygen than chlorate, ClO l Lose an oxygen, move down the chart. l Move down the chart and the name of the anion is chlorite. l Move across to the acid and the name of this acid is chlorous acid.

Name these: §HNO 3 -nitric acid §H 2 CO 3 -carbonic acid §H 2 SO 3 - sulfurous acid §HNO 2 -nitrous acid §HC 2 H 3 O 2 -acetic acid §HClO 4 -perchloric acid