Model 1 – Ion Charges for Selected Elements



Name: ______________________________________________Date: ________________________ Mods: ________________Naming Compounds and MoleculesPart I: Naming Ionic CompoundsWhy?What are the structural units that make up ionic compounds and how are they named?When working in chemistry, it is often convenient to write a chemical in symbols. For example we might write down the substance table salt as NaCl. In talking about chemistry however, it is a bit tacky to say “en-ay see-ell” when we want to refer to a substance. Also, in formal writing we should use the name of the compound rather than its symbols. Therefore we need to learn how to say the proper names of ionic substances.Model 1 – Ion Charges for Selected Elements1 H+12Li+1Be+2Transition elementsN–3O–2F–13Na+1Mg+2Al+3P–3S–2Cl–14K+1Ca+2Fe+2Fe+3Cu+1 Cu+2Zn+2Br–15Rb+1Sr+2Ag+1Sn+2Sn+4I–16Ba+2Hg2+2Hg+2Pb+2Pb+4CationsAnionsBased on the information in Model 1:Identify three elements that form only one cation.Identify three elements that form only one anion.Identify three elements that form more than one cation.In what region of the periodic table are these “multiple ion” elements usually located? These are called “multivalent ions”.NaCl Sodium chlorideCaSCalcium sulfideAg2SSilver sulfideZn3P2 Zinc phosphideAl2O3 Aluminum oxide SrCl3 Strontium chlorideModel 2 – Ionic Compound Names (Metals that form one ion)Circle the symbol for the metal in each of the compounds in Model 2.Which element comes first in the name and formula of the compounds in Model 2—the metal or the nonmetal?Use the table of ions in Model 1 to answer the following questions:In the compound zinc phosphide, what is the charge on the zinc ion? ____________In the compound zinc phosphide, what is the charge on the phosphide ion? ____________Is there any other ratio of zinc and phosphorus ions that could exist? For instance, could you have Zn2P or ZnP2? Explain your answer.Describe how the names of the nonmetal elements in Model 2 are changed when they are in their anion forms.Name the following ionic compounds using what you learned from Model 2.Li2O______________________________________________MgF2______________________________________________Al2S3______________________________________________K3N______________________________________________Provide the chemical formula for each of the following ionic compounds. Barium chloride______________________________________________Magnesium oxide______________________________________________Read This!When the metal in an ionic compound always forms an ion with the same charge, you need not indicate that charge as part of the compound name. However, some atoms have the ability to form more than one type of ion. This can make naming confusing. You can’t simply refer to a compound of copper and oxygen as “copper oxide.” People won’t know which compound you are referring to—CuO or Cu2O.Cu2O Copper(I) oxideCuO SnF2SnF4Copper(II) oxideTin(II) fluoride Tin(IV) fluoridePbOLead(II) oxidePbO2 Lead(IV) oxide FeCl2 Iron(II) chloride FeCl3 Iron(III) chlorideModel 3 – Ionic Compound Names (Metals that form multiple ions, aka Multivalent Ions)Describe the most obvious difference between the names in Model 3 and those in Model 2.Keeping in mind that the sum of the charges in an ionic compound must equal zero, use the chemical formulas in Model 3 to answer the following questions:Identify the charge on the copper cations in copper(I) oxide and copper(II) oxide, respectively.Identify the charge on the iron cations in iron(II) chloride and iron(III) chloride, respectively.What do the Roman numerals in the compounds described in Question 10 indicate?Fill in the table below using what you’ve learned from Model poundCharge on CationName of the CompoundPbCl4Pb4+Lead(IV) chlorideFe2O3SnOCuBr2For each of the compounds in the table below, determine the type of metal in the compound (check the appropriate column) and then name the compound using the correct naming method.Metal forms only one ionMetal forms multiple ionsNameMgOAg3NSnCl2CuF2HgOPart II: Compounds with Polyatomic IonsWhy?Can a group of atoms have a charge?Do you know you eat a lot of “-ates”? Next time you look at a food label, read the ingredients and you will likely find a number of ingredients that end with “-ate,” such as sodium phosphate or calcium carbonate. Did you ever wonder what the chemical formulas of these ingredients look like? In this activity we will explore polyatomic ions, which are groups of atoms that carry a charge. These ions are found in our food ingredients, natural waterways, and many other chemical compounds you encounter every day.Consider the terms “monatomic” and “polyatomic” as they are used in Model 1. Write a definition for each of these terms. It may be helpful to break the words apart (i.e., poly – atomic). Make sure your group comes to consensus.Monatomic— Polyatomic—Model 4 – Common Polyatomic IonsPositive:NH4+Ammonium ionNegative:C2H3O2-AcetateCO3-2CarbonatePO4-3 PhosphateCN-CyanideO2-2PeroxideOH-HydroxideSO3-2SulfiteMnO4-PermanganateSO4-2SulfateClO-HypochloriteCrO4-2ChromateClO2-ChloriteCr2O7-2DichromateClO3-ChlorateC2O4-2OxalateClO4-PerchlorateHPO4-2Hydrogen PhosphateNO2-NitriteNO3-NitrateBrO2-BromiteBrO3-BromateHCO3-Hydrogen CarbonateHSO4-Hydrogen SulfateIO3-IodateWhat is the only polyatomic ion that is a cation? _________________________________Identify the polyatomic ion in each of these ionic compounds. Write out the name and formula of the ions including their charges.Ca(CO3)_____________________________________________________ Mg(OH)2_____________________________________________________ (NH4)Cl_____________________________________________________Model 5 – Ionic Compounds with PolyatomicsCompound NameIon Symbols and ChargesChemical FormulaAmmonium phosphate1+NH43–PO4(NH4)3(PO4)Barium nitriteBa2+1–NO2Ba(NO2)2Ammonium sulfate1+NH42–SO4(NH4)2(SO4)Aluminum carbonateAl3+2–CO3Al2(CO3)3Iron(III) hydroxideFe3+OH1–Fe(OH)3Potassium nitrateK1+1–NO3K(NO3)Consider the compound iron(III) hydroxide in Model 5.How many hydroxide ions (OH)–1 are combined with an iron(III) ion (Fe+3)?Is your answer to part a the only combination of iron(III) and hydroxide that should exist in nature? Explain.Consider the compound barium nitrite in Model 5.What does the subscripted “2” inside the parentheses of the chemical formula tell you about the compound?Ba(NO2)2What does the subscripted “2” outside the parentheses of the chemical formula tell you about the compound?Ba(NO2)2A student writes the chemical formula for the ionic compound calcium hydroxide as CaOH2.Write the chemical formula for each ion in the compound. Calcium:Hydroxide:Why is the student’s chemical formula for the compound calcium hydroxide wrong?Many of the chemical formulas in Model 3 include parentheses. Which one of the following rules summarizes the appropriate use of parentheses in polyatomic ionic compounds? For the three rules that do not apply in all cases, show at least one counter example from the chemical formulas in Model 3.Parentheses are used around any ion that is used more than once in a formula unit. Parentheses are used around any polyatomic ion.Write chemical formulas for the following ionic compounds with polyatomics.Calcium sulfate__________________________________________________Copper(II) nitrate__________________________________________________Lithium phosphate__________________________________________________Potassium permanganate__________________________________________________Aluminum sulfite__________________________________________________Magnesium hydrogen carbonate _______________________________Name the following ternary ionic compounds.BaSO4__________________________________________________NH4NO3__________________________________________________K2Cr2O7__________________________________________________Fe(NO3)3__________________________________________________Mg(CH3COO)2__________________________________________________Al2(CO3)3 __________________________________________________Part III: Naming Molecular CompoundsWhy?How are the chemical formula and name of a molecular compound related?When you began chemistry class this year, you probably already knew that the chemical formula for car- bon dioxide was CO2. Today you will find out why CO2 is named that way. Naming chemical compounds correctly is of paramount importance. The slight difference between the names carbon monoxide (CO, a poisonous, deadly gas) and carbon dioxide (CO2, a greenhouse gas that we exhale when we breathe out) can be the difference between life and death! In this activity you will learn the naming system for molecu- lar compounds.Model 6 – Molecular CompoundsMolecular FormulaNumber of Atoms of First ElementNumber of Atoms of Second ElementName of CompoundClFChlorine monofluorideClF515Chlorine pentafluorideCOCarbon monoxideCO2Carbon dioxideCl2ODichlorine monoxidePCl5Phosphorus pentachlrorideN2O5Dinitrogen pentoxideFill in the table to indicate the number of atoms of each type in the molecular formula.Examine the molecular formulas given in Model 6 for various molecular compounds.How many different elements are present in each compound shown?Do the compounds combine metals with metals, metals with nonmetals, or nonmetals with nonmetals?Based on your answer to b, what type of bonding must be involved in molecular compounds?Assuming that the name of the compound gives a clue to its molecular formula, predict how many atoms each of these prefixes indicates, and provide two examples.mono- di- penta-Model 7 – Prefixes and SuffixesPrefixNumerical ValueMolecular FormulaName of Compoundmono-BCl3Boron trichloridedi-SF6Sulfur hexafluoridetri-IF7Iodine heptafluoridetetra-NI3Nitrogen triiodidepenta-N2O4Dinitrogen tetroxidehexa-Cl2ODichlorine monoxidehepta-P4O10Tetraphosphorus decoxideocta-B5H9Pentaboron nonahydridenona-Br3O8Tribromine octoxidedeca-ClFChlorine monofluorideExamine the prefixes in Model 7. Fill in the numerical value that corresponds to each prefix.What suffix (ending) do all the compound names in Model 7 have in common?Carefully examine the names of the compounds in Model 7. When is a prefix NOT used in front of the name of an element?Consider the compound NO.Which element, nitrogen or oxygen, would require a prefix in the molecule name? Explain your answer.Name the molecule NO.Find two compounds in Model 7 that contain a subscript of “4” in their molecular formula.List the formulas and names for the two compounds.What is different about the spelling of the prefix meaning “four” in these two names?Find two compounds in Model 7 that contain the prefix “mono-” in their names.List the formulas and names for the two compounds.What is different about the spelling of the prefix meaning “one” in these two names?Identify any remaining names of compounds in Model 7 where the prefixes that do not exactly match the spelling shown in the prefix table.Use your answers to Questions 30-32 to write a guideline for how and when to modify a prefix name for a molecular compound. Come to a consensus within your group.Using the rules your group developed in Question 33, name each of the following molecular compounds.Molecular FormulaMolecule NamePBr3SCl4N2F2SO3BrFWrite molecular formulas for the following compounds.Molecular FormulaMolecule NameDisulfur decafluorideCarbon tetrachlorideOxygen difluorideDinitrogen trioxideTetraphosphorus heptasulfideExtension QuestionsThis activity focused on ionic and molecular (covalent) compounds. Notice that the formulas for both types of compounds can look very similar, even though their names are quite different:Chemical FormulaType of Compound/BondingCompound NameMgF2IonicMagnesium fluorideCuF2IonicCopper(II) fluorideSF2Molecular (covalent)Sulfur difluorideNaBrIonicSodium bromideAuBrIonicGold(I) bromideIBrMolecular (covalent)Iodine monobromideIdentify two differences between the names or formulas for ionic compounds versus those for binary molecular compounds. Names and Formulas of Ionic CompoundsNames and Formula ofMolecular (Covalent) CompoundsDifferencesUse complete sentences to explain why AlCl3 is called “aluminum chloride” (no prefix required), but BCl3 is called “boron trichloride.”In the table below, first identify the type of bonding present in each compounds. Then fill in the missing name or formula for each compound using the appropriate set of rules.Chemical FormulaType of Compound/BondingCompound NamePbI2BaCl2Se2S6Xenon tetrafluorideSodium phosphideDinitrogen pentoxideCobalt(III) bromide ................
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