4 Objectives for 9.1 (pgs )By the end of this section you WILL be able to…ID charges of monatomic ions by using PTName ionsDefine polyatomic ion and write names and formulas of most common onesID two common endings for the names of most polyatomic ions
5 Naming Ions Monatomic -Ions formed from a single atom -Charge determined by number of valence electronsNOTHING NEW!Cations-Positively charged-Form when elements LOSE electrons-Usually what type of elements?
6 Naming Cations-The name of the element followed by the word ion.-For example:Na+ is sodium ion, Mg2+ is Magnesium IonAnions-Negatively charged-Form when elements GAIN electrons-Usually form from what type of elements?
7 Naming Anions-Named for the element but have the suffix –ideFor Example:Cl- is chloride N3- is nitride
8 Ions of Transition Metals (p. 255) Since “s” and “d” valence electrons are available, transition metals may form cations with different charges (E.g. Fe2+ and Fe3+)Stock System of naming uses a Roman numeral to designate the charge on the ion-For Example:iron (II) and iron (III) – preferred over Classical naming systemIf the transition metal only forms one ion you do not have to use the stock system
9 Polyatomic IonsIons that are made up of two or more covalently bonded atoms yet still have a net chargeThey behave like ions when bonding because of excess electrons, or excess protonsTo form some of these ions, BOTH electrons to be shared come from one atomWhat type of bond is this?-Coordinate Covalent
10 Oxyanions Most of the common polyatomic ions are oxyanions What do you think oxyanion means?-These anions contain different numbers of oxygen atomsWe will use the suffixes –ite and –ate to show how many oxygen are on each
11 -ate indicates the ion with more oxygen atoms -ite indicates the ion with less oxygen atomsBFAt corner will help us identify how many oxygenIf central atom is in the BFAt corner 3 oxygen atoms makes it an –ate 2 oxygen atoms is an –iteIf central atom is out of the BFAt corner 4 oxygen atoms makes it an –ate and 3 oxygen atoms is an - ite
12 Practice naming these… SO42-, SO32-, NO2-, NO3-, F-, ClO2-, ClO3-Respectively, they are sulfate, sulfite, nitrite, nitrate, fluoride, chlorite, and chlorateYou will need to memorize the charges!
13 Sometimes hydrogen appears at the beginning of an oxyanion This just changes the name tohydrogen ___ ate (or ite)For Example:HSO3 -2 is called hydrogen sulfiteHSO4-2 is called________________
14 Prefixes The prefix hypo- means less (think hypothermia) This means there is one less oxygen than the oxyanion with the –ite ending.For example:ClO- is called hypochloriteSO2-2 would be called_________________
15 The prefix per- indicates that there is one MORE oxygen than the oxyanion with the –ate ending. For Example:ClO4- is called perchloratePO53- is called _______________
16 Time to do work! Make flashcards for your polyatomic ions Memorize their chargesUse the BFAt corner to determine if they are –ite or -ateEnd of section 9.1 What are your questions?
17 9.2 Naming and Writing Formulas Goals for this section…You will be able to…Apply the rules for naming and writing formulas for binary ionic compoundsApply the rules for naming and writing formulas for compounds with polyatomic Ions9.2 Naming and Writing Formulas
18 9.2 Naming and Writing Formulas for Ionic Compounds Binary Compound-Compounds composed of two different types of elementsNaming Binary Ionic CompoundsWrite the name of the cationWrite the name of the anionFor metals with more than one oxidation state, use the STOCK SYSTEM!For example: Iron (III) Chloride = FeCl3
19 Writing Formulas for Binary Ionic Compounds Ion Charge Method uses charges of ions to determine quantity of each ion in a compoundThe net charges of a compound = 0Steps to writing balanced FormulasWrite the symbol and charge for each ion present. Write the cation first then the anion.Examples:Na+ Cl or Ca2+ Cl-
20 Adjust subscripts by using the cross-over method. Examples: Na Cl or Ca Cl-NaCl CaCl2Reduce if necessary. Subscripts should be in simplest whole number ratio.1112
21 The cross-over method also works for polyatomic ions The cross-over method also works for polyatomic ions. However, you must place parentheses around the entire ion to signify more than one.Try these:Lead (II) SulfateBarium ChlorideIron (II) acetateAmmonium CarbonateTin (IV) chromate
23 Compounds with Polyatomic Ions Write the symbol of the cation followed by the formula for the anionCross over to balance chargesPlace parentheses around the polyatomic ion if there is more than one
24 Naming Compounds with Polyatomic Ions Memorize formula and charges of polyatomic ions (quiz is coming up)Name the cation (don’t forget about the stock system if needed)Name the anionExamples:A. Ca(OH)2a. Calcium hydroxideB. FeSO4b. Iron (II) sulfate
25 The reward of a thing well done is to have done it -Emerson 9.3 Naming and Writing Formulas for Molecular CompoundsInterpret the prefixes in the names of molecular compounds in terms of their chemical formulasApply the rules for naming and writing formulas for binary molecular compounds
26 Naming Binary Molecular Compounds Name the first element in the formulaUse the appropriate prefix to show how many of that atom are present (see page 269)Name the second elementUse the appropriate prefix to show how many of that atom are presentAdd the suffix –ide to show that it is a binary compound
29 Writing Formulas for Binary Molecular Compounds Use prefixes to tell you how many of each atom are present in the compoundDinitrogen tetroxideN2O4Iodine heptafluorideIF7
30 9.4 Naming and Writing Formulas for Acids and Bases “If I set for myself a task, be it so trifling, I shall see it through. How else shall I have confidence in myself to do important things?”-George ClasonGoals:Apply the rules for naming acidsApply the rules in reverse to write acidsApply the rules for naming bases
31 Acids and Bases Naming and Formula Writing -a substance that contains one or more hydrogen atoms and produces hydrogen ions (H+) when dissolved in water-The general form is HnX- The name is dependent upon the name of the anion
32 Rules!Rule 1 – if the anion ends in “-ide”, the acid name begins with “hydro” and ends with “-ic” (binary acid)(E.g. HCl = hydro-chlor-ic acid)Rule 2 – if the anion ends in “-ite”, the acid name ends with “-ous” (oxyacid). (no hydro)(E.g. H2SO3 = sulfur-ous acid)
33 Rule 3 - if the anion starts with “hypo” and ends with “-ite”, the acid name starts with “hypo” and ends with “-ous” (E.g. HClO = hypo-chlor-ous acid)Rule 4 – if the anion ends in “-ate”, the acid name ends with “-ic” (E.g. HNO3 = nitr-ic acid)Rule 5 - if the anion starts with “per” and ends with “- ate”, the acid name starts with “per” and ends with “- ic” (E.g. HClO4 = per-chlor-ic acid)I ate so much I felt icky
34 Naming AcidsUse the same steps we did when writing formulas only backwards You should know your polyatomic Ions by now (they’re not going away)
35 Naming BasesBasesan ionic compound that produces hydroxide ions (OH-) when dissolved in waterNaming Bases-Name bases as you would any other ionic compound
36 Laws of Definite and Multiple Proportions The Law of Definite Proportions - elements combine in a definite mass ratio regardless of the size of the sample produced (e.g. water is always 89% oxygen and 11% hydrogen by mass)The Law of Multiple Proportions – whenever the same two elements form more than one compound, the different masses of one element that combine with a fixed mass of the other element are in a ratio of small whole numbersExamples: H2O and H2O2 CO and CO2 N2O and N2O4
37 Classical Naming System Classical System of naming using the Latin name of the element and the suffix “-ous” to show the lower of two oxidation states (E.g. ferrous)The suffix “-ic” is used to show the higher of two oxidation states in the Classical System (E.g. ferric)