Presentation on theme: "CHAPTER 9: Chemical Names and Formulas"— Presentation transcript:
1 CHAPTER 9: Chemical Names and Formulas Objectives:To be able to name ionic and molecular compounds, and acids.2. To be able to write the formulas of ionic and molecular compounds, and acids.
2 Different Types of Formulas and Names Ionic compoundsMolecular compounds (molecules)Acids (a special type of molecule)
3 Ionic CompoundsMonatomic ions are ions of a single atom with a positive ornegative charge resulting from the loss or gain of one ormore valence electrons.Monatomic cations: Monatomic anions:Na+, Ca2+ Cl-, N3-Naming monatomic cations: Naming monatomic anions:Cations for groups 1, 2, & Anion start with the samemetals have the same name as stem and end with -ide.the atoms, followed by ion or This is followed by ion orcation anion.Na+ is sodium ion or sodium Cl- is chloride ion orcation chloride anion.
4 Other Names of Monatomic Ions Ion Symbol Ion NameLi+ lithium ion (or cation)Ca2+ calcium ion (or cation)Al3+ aluminum ion (or cation)F- fluoride ion (or anion)O2- oxide ion (or anion)N3- nitride ion (or anion)P phosphide ion (or anion)
5 Naming Binary Ionic Compounds Binary Ionic Compounds are composed of ions oftwo elements.To Name Binary Ionic Compounds, place the cationname first, followed by the anion name.Formulas NamesNaCl sodium chlorideCaF2 calcium fluorideMg3N2 magnesium nitrideAlP aluminum phosphideK2Se potassium selenide
6 Polyatomic IonsPolyatomic ions are ions composed of more than one type of atom (usually nonmentals) covalently bonded.Examples of Polyatomic ions:NH PO SO OH-For naming polyatomic ions, you can use your common ion table to get the name.Compounds NamesNH4Cl ammonium chlorideNa3PO4 sodium phosphateAl2(CO3)3 aluminum carbonateCu(NO2)2 copper(II) nitrite
7 Naming Ions & Ionic Compounds of Transition Metals Since some transition metals may have more then one charge, the charges of the cations must be determined and represented when naming transition metal ions and compounds with transition metal ions.For example, iron is a transition metal and can have two common charges, Fe2+ and Fe3+.When naming these ions, we use the Stock system which uses Roman numerals in parentheses after the metal name.If the charge of the metal is not given directly, you must determine it by using the formula given.Ion Name of Ion Ionic Compound Name of CompoundFe iron(II) ion FeCl iron(II) chlorideFe iron(III) ion FeCl iron(III) chlorideCu copper(I) ion CuF copper(I) fluoridePb lead(IV) ion PbI lead(IV) iodide
8 Steps to Writing Formulas of Ionic Compounds Write the symbols of both ions including their charges remembering that the cation is placed first followed by the anion. sodium oxide Na+ O2-Crisscross the value of the charges. This will make it so that the charges are balanced.Na O2-Rewrite your new formula and make sure the charges cancel each other. Na2O two Na+ = total chargeone O2- = is zeroIf the charge is 1- or 1+, leave the number 1 out the formula since it is understood to be there.5. If necessary, reduce the numbers of each atom by a common denominator since formula units represent the lowest ratio of ions in an ionic compound.6. If there is more then one polyatomic ion present, use ( ) around the ion and then place the subscript outside of the ( ).
9 Formula Practice: Binary Ionic Compounds Name of Compound Ions Formulaaluminum iodide Al3+ I- AlI3calcium phosphide Ca2+ P3- Ca3P2barium sulfide Ba2+ S2- BaSrubidium bromide Rb+ Br- RbBrstrontium nitride Sr2+ N Sr3Ncopper(II) chloride Cu2+ Cl- CuCl2chromium(III) oxide Cr3+ O2- Cr2O3
10 Naming Ionic Compounds with Transition Metals It is necessary to determine the charge of a transition metals that can have more then one charge in order to name it.This can be done by using the formula given and determining the charge of the anion first.Remember that the total charges of the anion and cation must cancel each other out.Formula Ions NameCuCl Cu+ Cl copper(I) chlorideCuCl2 Cu2+ Cl copper(II) chlorideFe2O Fe2+ O iron(II) oxideFe2O Fe3+ O iron(III) oxidePbO2 Pb O2- lead(IV) oxidePbCO3 Pb2+ CO lead(II) carbonate
11 Formula Making: Compounds with Polyatomic Ions Formula making with polyatomic ions is very similar to what you have learned so far.Just DON’T forget to use ( ) around polyatomic ions when there is more then one of them!Names Ions Formulamagnesium sulfate Mg2+ SO MgSO4ammonium fluoride NH4+ F NH4Cllithium carbonate Li CO Li2CO3calcium nitrate Ca NO Ca(NO3)2beryllium hydroxide Be OH Be(OH)2
12 Naming Binary Molecular Compounds When two nonmetals combine, they form a molecular compound whose formula shows the actual number of each kind of atom found in a molecule of the compound.To name these compounds, we use a similar method to naming ionic cmps (see endings) except we can use prefixes to denote number of each atoms.Note: when there is only atom of the first element in the compoundmono- is not used before the atom’s name.Note: when using prefixes with atoms that start with a vowel, the last vowel of the prefix is dropped.
14 Naming AcidsFor now, the acids that we will learn how to name contain hydrogen ions, H+. (formulas start with H)Naming Rules:When the anion name ends in -ide, the stem of the anion name begins with the prefix hydro- and ends with -ic. The name is then followed by the word acid.When the anion name ends in -ite, the anion ends with -ous, followed by the word acid.When the anion name ends in -ate, the anion name ends with -ic, followed by the word acid.