3Atoms and Ions are electrically neutral. Same number of p+ and e-- atoms with a charge (+ or -)Made by gaining or losingOnly electrons can move
4F1- O2- An Anion is… A negative ion = electrons. Nonmetals gain electrons.Charge is written as a superscript on the right.F1-Has gained electron (-ide is new ending = )O2-Gained electrons ( )
5K1+ Ca2+ A Cation is… A positive ion = electrons. lose electrons Has lost electron (no name change for positive ions)More protons than electronsCa2+Has lost electrons
6Predicting Ionic Charges Group 1A:Lose electron to form ionsH1+Li1+Na1+K1+Rb1+
7Predicting Ionic Charges Group 2A:Loses electrons to form ionsBe2+Mg2+Ca2+Sr2+Ba2+
8Predicting Ionic Charges Loses electrons to formionsGroup 3A:B3+Al3+Ga3+
9Predicting Ionic Charges ! Group 4A elements rarely form ions (they tend to share)Group 4A: Do they lose 4 electrons or gain 4 electrons?
10Predicting Ionic Charges NitrideGains _electrons to formionsGroup 5A:P3-PhosphideAs3-Arsenide
11Predicting Ionic Charges OxideGains electrons to form ionsGroup 6A:S2-SulfideSe2-Selenide
12Predicting Ionic Charges Gains _ electron to form ionsGroup 7A:F1-FluorideBr1-BromideCl1-ChlorideI1-Iodide
13Predicting Ionic Charges Group 8A: Stable noble gases form ions!
14Predicting Ionic Charges Group B elements: Many transition elementshave possible charge.Use of Roman numerals to show chargesIron (II) =Iron (III) =Show roman numerals up to 5.
15Naming Cationssystem – use roman numerals in parenthesis to indicate the charge value2. Classical method – uses root word with suffixes (-ous, -ic)Does not give true value
16Naming cationsIf the charge is always the (like in the Group A metals) just write the of the metal.Calcium = 𝐶𝑎 +2metals can have more than one type of charge.Indicate charge as roman numeral in after the name of the metal (Table 9.2, p.255)Iron (IV) =
17Predicting Ionic Charges Some elements alsohave more than one possible charge.Tin (II) =Lead ( ) = Pb2+Tin (IV) =Lead ( ) = Pb 4+
18Predicting Ionic Charges Group elements:Some transition elementshave only one possible oxidation state, such as these three:**Do not use roman numerals for theseSilver =Zinc =Cadmium =
19Practice by naming these: Ca2+Al3+Fe3+Fe2+Pb2+Li+
20Write symbols for these: Potassium ionMagnesium ionCopper (II) ionChromium (IV) ionBarium ionMercury (II) ion
21Anions are the same charge Change the ending to _ Naming AnionsAnions are the same chargeChange the ending to _F1- a Fluorine atom will become a ion.
23Write symbols for these: Sulfide ionIodide ionPhosphide ionStrontium ion
24Polyatomic ions are…Groups of atoms that together, have an charge, and one name.Usually end in – or _Acetate: C2H3O2-Nitr : NO3-Nitr : NO2-Permanganate: MnO4-Hydroxide: OH- and Cyanide: CN-?
25Know Table 9.3 on page 257 Sulf : SO42- Phosph : PO43- Sulf : SO32- Carbonate: CO32-Chromate: CrO42-Dichromate: Cr2O72-Phosph : PO43-Phosph : PO33-Ammonium: NH41+(One of the few positive polyatomic ions)
26H + Polyatomic ion =….If the polyatomic ion begins with H, then put “hydrogen” in front of the polyatomic ion: H CO32- → HCO31- hydrogen + carbonate → hydrogen carbonate ionHSO3HPO4HCO3
27Helpful Hints on Oxy-Anions 1. _________: smaller # of oxygen2. _________: larger # of oxygenEx.NO3- ____________________________NO2- ____________________________SO42- ____________________________SO32- ____________________________
28A Guide to Determine Whether the –ate Formula is –XO3 or –XO4: 123456131415161718Transition MetalsBCNSiPSClAsSeBrI
29Section 9.2 Naming and Writing Formulas for Ionic Compounds
30Writing Ionic Compound Formulas Example: Iron (III) chloride1. Write the cation and anion with CHARGES!2. Balance charges using the criss-cross method with subscripts, if necessary. Use parentheses if you need more than one of a polyatomic ion to balance subscripts.
31Writing Ionic Compound Formulas Example: Aluminum sulfide1. Write the cation and anion with CHARGES!2. Balance charges using the criss-cross method with subscripts, if necessary. Use parentheses if you need more than one of a polyatomic ion to balance subscripts.
32Writing Ionic Compound Formulas Example: Zinc hydroxide1. Write the cation and anion with CHARGES!2. Balance charges using the criss-cross method with subscripts, if necessary. Use parentheses if you need more than one of a polyatomic ion to balance subscripts.
33Writing Ionic Compound Formulas Example: Magnesium carbonate (note the 2 word name)1. Write the formulas for the cation and anion, including CHARGES!Mg2+CO32-2. Check to see if charges are balanced.They are balanced!
34Writing Ionic Compound Formulas Example: Barium nitrate (note the 2 word name)1. Write the cation and anion with CHARGES!2. Balance charges using the criss-cross method with subscripts, if necessary. Use parentheses if you need more than one of a polyatomic ion to balance subscripts.
35Writing Ionic Compound Formulas Example: Ammonium sulfate1. Write the cation and anion with CHARGES!2. Balance charges using the criss-cross method with subscripts, if necessary. Use parentheses if you need more than one of a polyatomic ion to balance subscripts.
36Writing Ionic Compound Formulas Example: Aluminum phosphate1. Write the formulas for the cation and anion, including CHARGES!Al3+PO43-They ARE balanced!2. Check to see if charges are balanced.
37Naming Ionic Compounds 1. Cation , then anion2. Monatomic cation = name of the elementCa2+ = ion3. Monatomic anion = root + -ideCl- =CaCl2 =
38Naming Ionic Compounds (Metals with multiple oxidation states)If the metal can have more than one charge ( ), use a Roman numeral in their name:PbCl2 use the to find the charge on the cation (chloride is always 1-)is the lead ( ) cationPbCl2 = lead ( ) chloride
39Things to look for:If cations have ( ), the number in parenthesis is their .If anions end in –ide, they are probably off the periodic table ( )If anion ends in -ate or –ite, then it is
40Practice by writing the formula or name as required… Iron (II) PhosphateStannous FluoridePotassium SulfideAmmonium ChromateMgSO4FeCl3
41Section 9.3 Naming and Writing Formulas for Molecular Compounds
42Molecular compounds are… Made of onlySmallest part is aCan’t use charges to figure out how many of each atom (there are no charges present / they share electrons)
43Molecular compounds are easier! compounds use to determine how many of each.Figure out charges and criss-cross numbers.Molecular compounds: the name tells you the number of atoms.Uses to tell you the exact number of each element present!
45Prefixes Prefix + name -ide To write the name, include:One exception is we don’t write if there is only of the element.Normally, we do not have double vowels when writing names (oa oo)Prefix + name -ide
46Practice by naming these: N2ONO2Cl2O7CBr4CO2BaCl2
48Section 9.4 Naming and Writing Formulas for Acids and Bases
49Acids are…Compounds that give off ions (H+) when dissolved in water (the Arrhenius definition)Formula starts with .Always be some Hydrogen next to an .determines the name.
50Rules for Naming acids: Name it as a normal compound first If the anion attached to hydrogen ends in -ide, put the prefix and change -ide to - acidIn other words, if it’s just Hydrogen and one other nonmetalHCl =H2S =acidacid
51Naming AcidsIf the anion has oxygen in it, then it ends in -ate or -iteChange -ate to -ic acid (use no prefix)Example: HNO Hydrogen + nitrate =Change -ite to -ous acid (use no prefix)Example: HNO Hydrogen + nitrite =
52Naming Acids ____-ide ____-ate ____-ite hydro-___-ic acid Normal ending____-ide____-ate____-iteAcid name is…hydro-___-ic acid_____-ic acid_____-ous acid
53Practice by naming these: HFH3PH2SO4H2SO3HCNH3PO4
54Writing Acid Formulas – in reverse! Hydrogen will be listed firstThe name will tell you theBe sure the charges cancel out.Starts with hydro?No hydro?Anion is , ends in –ide-ate anion comes from – ending-ite anion comes from – ending
55Write formulas for these: hydroiodic acidchloric acidcarbonic acidphosphorous acidhydrobromic acid
56Names and Formulas for Bases Base - an ionic compound that produces ions ( ) when dissolved in water (the Arrhenius definition)Named the same way as other ionic compounds:Name of cation ( ) followed by name of anion (which will be ).
57Names and Formulas for Bases NaOH =Ca(OH)2 =To write the formula:Write symbol for metal cationFollowed by hydroxide ion (OH1-)Use criss-cross method to balance the charges.
58Practice by writing the formula for the following: Magnesium hydroxideIron (III) hydroxideZinc hydroxide
59Section 9.5 The Laws Governing Formulas and Names
60Some Laws:Law of Proportions- in a sample of a chemical compound, the of the are always in the proportions.In every molecule of H2O (water), the mass ratio of H:O is 1:8
61Some Laws:Law of Proportions- Whenever two elements form than one compound, the masses of one element that combine with the mass of the other element are in the ratio of smallH2O (water) and H2O2 (hydrogen peroxide)2: :22g:16g g:32g
62https://www.youtube.com/watch?v=0OOcpiTiXzMLaw of Definite Proportions - Law of Multiple Proportionsby Brightstorm
63Summary of Naming and Formula Writing For naming, follow the flowchart- Figure 9.20, page 277For writing formulas, follow the flowchart from Figure 9.22, page 278
64Helpful to remember...1. In ionic compounds, the net charge is _ (criss-cross method)2. Put -ide at the end of monatomic3. An -ite or -ate ending means there is a ion that has4. Prefixes generally mean ; they show the number of each atom
65Helpful to remember...5. A Roman numeral after the name of a cation is the of the cation