Chapter 3

Chemical Names and FormulasChapter 9Section 1Naming IonsSection 1 Learning Targets9.1.1 I can identify the charges of monatomic ions by using the periodic table, and name the ions.9.1.2 I can define a polyatomic ion and write the names and formulas of the most common polyatomic ions.9.1.3 I can identify the two common endings for the names of most polyatomic ions.Monatomic IonsMonatomic ion consist of a single atom with a positive or negative charge resulting from the gain or loss of one or more valence electrons.CationsWhen the metals in Groups 1A, 2A and 3A lose electrons they form cations with positive charges equal to the group number.The names of these ions are the same as the element name with ion after it.

AnionsNonmetals of Groups 5A, 6A, and 7A gain electrons to form anions with negative charges.The charge of any ion of a Group A nonmetal is determined by subtracting 8 from the group number.

Group 7A so 7-8=-1; 6A so 6-8=-2; 5A so 5-8=-3The names of these ions change. The endings are dropped and replaced by ide ion (sulfur = sulfide ion).Groups 4A and 8A elements do not usually form ions.

Examples:Name the ions formed by these elements and classify them as anions or cations:Selenium ____________________Barium ____________________Phosphorus ____________________Examples:Name the following ions:I- ____________________N3- ____________________O2- ____________________

This table can be found on page 254Ions of Transition MetalsThe charges of the cations of many transition metal ions must be determined from the number of electrons lost.

Two methods classical (-ous and ic endings) or the stock system (roman numerals).Preferred is the stock system because the roman numeral tells the charge.

So why do we use Roman numerals or the classical method anyway?

This table can be found on page 255Examples:Name the following ions:Fe3+ ____________________Cu+ ____________________Mn4+ ____________________Sn2+ ____________________Pb4+ ____________________Polyatomic IonsPolyatomic ion composed of more than one atom.The names of most polyatomic anions end in ate or ite.There are very few positive polyatomic ions.

Examples:Write the symbol or formula (including charge) for each of the following ions:Ammonium ion ____________________Chromate ion ____________________Tin (II) ion ____________________Nitrate ion ____________________Examples:Name the following ions:OH- ____________________Pb4+ ____________________SO42- ____________________O2- ____________________Section 2Naming and Writing Formulas for Ionic CompoundsSection 2 Learning Targets9.2.1 I can apply the rules for naming and writing formulas for binary ionic compounds.9.2.2 I can apply the rules for naming and writing formulas for compounds with polyatomic ions.Binary Ionic CompoundsIn the past anyone who created a compound named it.Currently there is a system.Antione Lavoisier decided it was too difficult to memorize unrelated names and formulas.Naming Binary Ionic CompoundsBinary compound compound of two elements and can be either ionic or molecular.To name binary ionic compounds, place the name of the cation first followed by the anion name.Examples:Write the names of the following binary ionic compounds:NaCl ____________________MgBr2 ____________________SrO ____________________Li2O ____________________Be3N2 ____________________For transition metals you need to figure the charge of the metal and put that in parentheses as a Roman numeral.Examples:Write the names of the following binary ionic compounds:SnO2 ____________________Fe2O3 ____________________MnO ____________________MnO2 ____________________Co3N2 ____________________Writing Formulas for Binary Ionic CompoundsWrite the symbol of the cation and then the anion. Add what ever subscripts are needed to balance the charges.

Examples:Write the formulas for the compounds formed from these pairs of ions:Ba2+, S2- ____________________Ca2+, N3- ____________________Li+, O2- ____________________Cu2+, I- ____________________Examples:Write the formulas for these compounds:Sodium iodide ____________________Potassium sulfide ____________________Calcium iodide ____________________For transition metals the Roman numeral tells the charge on the metal cation.Then the same as before, balance the charges.Examples:Write the formulas for the following compounds:Tin (IV) nitride ____________________Copper (I) oxide ____________________Copper (II) oxide ____________________Lead (II) sulfide ____________________Iron (III) oxide ____________________Compounds with Polyatomic IonsWrite the symbol for the cation followed by the formula for the polyatomic ion and balance the charges.HINT: if you need more than one polyatomic ion use parenthesis.Examples:Write the formula for the following compounds:Ammonium nitride ____________________Ammonium cyanide ___________________Calcium carbonate ____________________Tin (IV) sulfite ____________________Magnesium phosphate __________________

Naming Compounds with Polyatomic IonsTo name a compound containing a polyatomic ion, state the cation first and then the anion, just as you did for binary ionic compounds.Examples:Name the following compounds:Sn2(CO3)4 ____________________Mg(CN)2 ____________________Fe(NO3)3 ____________________(NH4)3PO4 ____________________CuSO4 ____________________Section 3Naming and Writing Formulas for Molecular CompoundsSection 3 Learning Targets9.3.1 I can interpret the prefixes in the names of molecular compounds in terms of their chemical formulas.9.3.2 I can apply the rules for naming and writing formulas for binary molecular compounds.Naming Binary Molecular CompoundsRemember binary means 2.Molecular compounds have covalent bonds not ionic like previous sections.A prefix in the name of a binary molecular compound tells you how many atoms of each element are present in each molecule of the compound.Ending is still ide so make sure youre telling the difference between molecular and ionic.

Examples:Write the name for the following binary molecular compounds:NCl3 ____________________SO3 ____________________NI3 ____________________N2O3 ____________________N2H4 ____________________Writing Formulas for Binary Molecular CompoundsUse the prefixes in the name to tell you the subscripts of each element in the formula.Then write the correct symbols for the two elements with the appropriate subscripts.Examples:Write the formulas for the following binary molecular compounds:Phosphorus pentachloride __________________Iodine heptafluoride ____________________Chlorine trifluoride ____________________Iodine dioxide ____________________Diphosphorus trioxide ____________________Section 4Naming and Writing Formulas for Acids and BasesSection 4 Learning Targets9.4.1 I can apply three rules for naming acids.9.4.2 I can apply the rules in reverse to write the formulas for acids.9.4.3 I can apply the rules for naming bases.Naming AcidsAcid a compound that contains one or more hydrogen atoms and produces hydrogen ions (H+) when dissolved in water.

Rules for Naming AcidsWhen the name of the anion (X) ends in ide, the acid name begins with the prefix hydro-. The stem of the anion has the suffix ic and is followed by the word acid.HCl(aq) (X = chloride) is named hydrochloric acid.H2S(aq) (X = sulfide) is named hydrosulfuric acid.When the anion name ends in ite, the acid name is the stem of the anion with the suffix ous, followed by the word acid.H2SO3(aq) (X = sulfite) is named sulfurous acid.When the anion name ends in ate, the acid name is the stem of the anion with the suffix ic followed by the word acid.HNO3(aq) (X = nitrate) is named nitric acid.Examples:Write the names for the following acids:HNO2 ____________________HCN ____________________HMnO4 ____________________H2S ____________________HClO4 ____________________

Writing Formulas for AcidsUse the rules for writing the names of acids in reverse to write the formulas for acids.Examples:Write the formulas for the following acids:Carbonic acid ____________________Sulfurous acid ____________________Hydroiodic acid ____________________Nitrous acid ____________________Phosphoric acid ____________________Names and Formulas for BasesBase an ionic compound that produces hydroxide ions (OH-) when dissolved in water.Bases are named in the same way as other ionic compounds.The name of the cation is followed by the name of the anion.Formulas are written the same as for ionic compounds.Examples:Identify each compound as an acid or a base:Ba(OH)2 ____________________HClO4 ____________________Fe(OH)3 ____________________KOH ____________________Examples:Write the names for the following bases:Ba(OH)2 ____________________LiOH ____________________Pb(OH)2 ____________________Mg(OH)2 ____________________Al(OH)3 ____________________Section 5The Laws Governing Formulas and NamesSection 5 Learning Targets9.5.1 I can define the laws of definite proportions and multiple proportions.9.5.2 I can apply the rules for naming chemical compounds by using a flowchart.9.5.3 I can apply the rules for writing the formulas of chemical compounds by using a flowchart.The Laws of Definite and Multiple ProportionsThe rules for naming and writing formulas are possible because compounds form from the elements in predictable ways.These ways are summed up in two laws: the law of definite proportions and the law of multiple proportions.

The Law of Definite ProportionsStates that in samples of any chemical compound, the masses of the elements are always in the same proportions.The Law of Multiple ProportionsStates whenever the same two elements form more than one compound, the different masses of one element that combine with the same mass of the other element are in the ratio of small whole numbers.Practicing Skills: Naming Chemical CompoundsFollow the arrows and answer the questions on the flow chart to write the correct name for a compound.

Examples:Write the names for the following compounds:NaClO3 ____________________HClO4 ____________________KHSO4 ____________________Cl2O ___________________Examples:Write the names for the following compounds:SnO2 ____________________Ca(OH)2 ____________________K2CrO4 ____________________Fe(C2H3O2)3 ____________________SiCl4 ____________________Practicing Skills: Writing Chemical FormulasAn ide ending generally indicates a binary compound.Either ionic or covalent.An ite or ate ending means a polyatomic ion that includes oxygen is in the formula.An ic or ous ending shows that the compound may be an acid.

Practicing Skills: Writing Chemical FormulasPrefix in a name generally indicate the compound is molecular.A Roman numeral after the name of a cation shows the ionic charge of the cation.

Examples:Write the formulas for the following compounds:Calcium bromide ____________________Aluminum carbide ___________________Tin (IV) cyanide ____________________Strontium acetate ____________________Silver chloride ____________________Examples:Write the formulas for the following compounds:Nitrogen dioxide ____________________Lithium hydride ____________________Sodium silicate ____________________Acetic acid ____________________Hydrochloric acid ___________________