Chapter 7 Vanessa N. Prasad-Permaul CHM1025 Valencia College Chapter 7 1 © 2011 Pearson Education, Inc. Language of Chemistry

IUPAC  The International Union of Pure and Applied Chemistry, IUPAC, has set rules for naming compounds.  IUPAC set the rules for the naming and classification of inorganic compounds in  These rules, referred to as IUPAC nomenclature, are still in use today. © 2011 Pearson Education, Inc.Chapter 7 2

Classification of Compounds  Most inorganic compounds do not contain the element carbon.  The exceptions are carbon dioxide, CO 2, and carbonates, which contain the ion CO 3 2–.  There are five common classes of inorganic compounds: 1.Binary ionic 2.Ternary ionic 3.Binary molecular 4.Binary acid 5.Ternary oxyacid © 2011 Pearson Education, Inc.Chapter 7 3

Classification of Compounds, Continued  Below is a flow chart for the classification of inorganic compounds. © 2011 Pearson Education, Inc.Chapter 7 4

Example 7.1 Classifying Compounds and Acids Classify each of the following as a binary ionic compound, ternary ionic compound, binary molecular compound, binary acid, or ternary oxyacid: (a)calcium oxide, CaO (b)sulfur dioxide, SO 2 (c)silver chromate, Ag 2 CrO 4 (d)hydrofluoric acid, HF(aq) (e)carbonic acid, H 2 CO 3 (aq) Classify each of the following as a binary ionic compound, ternary ionic compound, binary molecular compound, binary acid, or ternary oxyacid: (a)carbon dioxide, CO 2 (b) potassium dichromate, K 2 Cr 2 O 7 (c)calcium fluoride, CaF 2 (d) nitric acid, HNO 3 (aq) (e) hydrochloric acid, HCl(aq) (f) phosphoric acid, H 3 PO 4 (aq) Practice Exercise

Classification of Ions  Recall, an ion is an atom or group of atoms with a charge.  A positively charged ion is called a cation.  A negatively charged ion is called an anion.  A group of atoms bound together that has an overall charge is called a polyatomic anion. © 2011 Pearson Education, Inc.Chapter 7 6

Classification of Ions, Continued  Below is a flow chart for the classification of ions. © 2011 Pearson Education, Inc.Chapter 7 7

Example 7.2 Classifying Cations and Anions Classify each of the following ions as a monoatomic cation, monoatomic anion, polyatomic cation, or polyatomic anion: (a)barium ion, Ba 2+ (b)chloride ion, Cl – (c)nickel(II) ion, Ni 2+ (d) chlorate ion, ClO 3 – Classify each of the following ions as a monoatomic cation, monoatomic anion, polyatomic cation, or polyatomic anion: (a)ammonium ion, NH 4 + (b) nitride ion, N 3– (c) permanganate ion, MnO 4 – (d) ferrous ion, Fe 2+ Practice Exercise

Monoatomic Cations  Metal atoms can lose valence electrons and become positively charged cations.  Cations are named for the parent atom followed by the word “ion.”  Na + is named “sodium ion.”  Al 3+ is named “aluminum ion.”  This rule applies for metals that usually form one ion. This includes the main group metals except tin and lead, along with Ag +, Zn 2+, and Cd 2+. © 2011 Pearson Education, Inc.Chapter 7 9

Ion Charges © 2011 Pearson Education, Inc.Chapter 7 10 Shown are the elements on the periodic table and their common charges.

Example 7.3 Names and Formulas of Monoatomic Cations Provide the formula for the following monoatomic cations: (a)barium ion(b)cobalt(II) ion Supply a systematic name for the following monoatomic cations: (a)Sn 4+ (b)Cu 2+ Practice Exercise

Monoatomic Anions  Nonmetals can gain valence electrons and become negatively charged anions.  Monoatomic anions are named by dropping the end of the element name and adding the suffix –ide.  Br - is the bromide ion.  O 2- is the oxide ion.  N 3- is the nitride ion. © 2011 Pearson Education, Inc.Chapter 7 12

Example 7.4 Names and Formulas of Monoatomic Anions Provide the formula for each of the following monoatomic anions: (a)fluoride ion(b)oxide ion Supply a systematic name for each of the following monoatomic anions: (a)Cl – (b)P 3– Practice Exercise

Polyatomic Anions  Polyatomic anions generally contain one or more elements combined with oxygen. These anions are called oxyanions.  Most oxyanions have names that end in the suffix -ate.  SO 4 2- is the sulfate ion.  NO 3 - is the nitrate ion. © 2011 Pearson Education, Inc.Chapter 7 14

Naming Oxyanions  Some oxyanions end in the suffix -ite.  NO 2 - is the nitrite ion.  SO 3 2- is the sulfite ion.  Notice that these oxyanions have one less oxygen: sulfate (SO 4 2- ) and nitrate (NO 3 - ).  The oxyanions that end in -ite each have one less oxygen than the oxyanions that end in - ate. © 2011 Pearson Education, Inc.Chapter 7 15

Some Common Polyatomic Ions © 2011 Pearson Education, Inc.Chapter 7 16

More Polyatomic Anions  The formula for the chlorate ion is ClO 3 -. What is the formula for the chlorite ion?  The suffix has changed from -ate to -ite. Chlorite must have one less oxygen then chlorate, so its formula is ClO 2 -.  Notice that the charge does not change as the number of oxygen atoms changes.  There are two common polyatomic ions that end in -ide: 1.Hydroxide, OH - 2.Cyanide, CN - © 2011 Pearson Education, Inc.Chapter 7 17

Example 7.5 Names and Formulas of Polyatomic Ions Provide a systematic name for each of the following polyatomic oxyanions: (a)CO 3 2– (b)CrO 4 2– (c)ClO 2 – (d)HSO 4 – Provide the formula for each of the following polyatomic oxyanions: (a)hydroxide ion (b)dichromate ion (c) hypochlorite ion (d)hydrogen carbonate ion Practice Exercise

Ionic Compounds  Binary ionic compounds contain two elements: one metal and one nonmetal.  NaCl and AlCl 3 are binary ionic compounds.  Ternary ionic compounds contain three elements, at least one metal and one nonmetal.  KNO 3 and Al(NO 3 ) 3 are ternary ionic compounds. © 2011 Pearson Education, Inc.Chapter 7 19

Metals that Form Multiple Ions  If a metal can form more than one cation, it is named for the parent, followed by the charge in Roman numerals in parentheses, followed by the word “ion.”  Fe 2+ is the iron(II) ion.  Fe 3+ is the iron(III) ion.  This is called the Stock system of naming cations. © 2011 Pearson Education, Inc.Chapter 7 20

Writing Ionic Formulas  An ionic compound is composed of positive and negative ions.  A formula unit is the simplest representative particle of an ionic compound.  A formula unit is neutral, so the total positive charge must equal the total negative charge in the formula unit.  When writing chemical formulas, the cation (metal) goes first and the anion (nonmetal) goes second. © 2011 Pearson Education, Inc.Chapter 7 21

Formulas of Ionic Compounds  If the ions in the ionic compound have the same charge, the formula unit contains one of each ion.  Na + and Cl - combine to form NaCl.  Mg 2+ and S 2- combine to form MgS.  If the charges are not equal, we must balance the positive and negative charges.  Ca 2+ and Cl - combine to form CaCl 2.  Na + and O 2- combine to form Na 2 O. © 2011 Pearson Education, Inc.Chapter 7 22

Crossover Rule  You can quickly verify that the chemical formula is written correctly by crossing over the charge on each ion.  The charge on the aluminum ion becomes the subscript for the oxygen, and the charge on the oxide ion becomes the subscript for the aluminum ion. © 2011 Pearson Education, Inc.Chapter 7 23

Example 7.6 Writing Formulas of Binary Ionic Compounds Write the chemical formula for the following binary compounds given their constituent ions: (a)copper(I) oxide (b)cadmium oxide (c)cobalt(III) oxide Write the chemical formula for the following binary compounds given their constituent ions: (a) iron(III) oxide (b) mercury(I) fluoride, Hg 2 2+ & F – (c)lead(II)sulfide (d) copper (II) chloride Practice Exercise

Formulas with Polyatomic Ions  Follow the same rules as binary ionic compounds; if the charges are equal, the formula has one of each ion.  Mg 2+ and SO 4 2- combine to form MgSO 4.  K + and ClO 3 - combine to form KClO 3.  If the charges are not equal, total charge must equal zero. If you have more than one polyatomic ion, it is placed in parentheses.  Al 3+ and CO 3 2- combine to form Al 2 (CO 3 ) 2. © 2011 Pearson Education, Inc.Chapter 7 25

Example 7.7 Writing Formulas of Ternary Ionic Compounds Write the chemical formula for each of the following ternary compounds given their constituent ions: (a)calcium carbonate, Ca 2+ and CO 3 2– (b)calcium hydroxide, Ca 2+ and OH – (c)calcium phosphate, Ca 2+ and PO 4 3– Chalk, CaCO 3 Chalk is an example of a ternary ionic compound composed of calcium ions and carbonate ions. Write the chemical formula for each of the following ternary compounds given their constituent ions: (a)copper(III) permanganate, Cu 3+ and MnO 4 – (b)iron(II) carbonate, Fe 2+ and CO 3 2– (c) potassium dichromate, K + and Cr 2 O 7 2– (d) sodium acetate. Na + and C 2 H 3 O 2 - Practice Exercise

Determining Ionic Charges  If an ionic compound contains a metal that can have more than one ionic charge, we must determine the charge on the ion. The sum total charge of an ionic compound must equal zero.  What is the charge on the chromium ion in Cr 3 N 2 ?  The charge on a nitride ion is always –3, so we have a total of six negative charges (2 × N 3- = 6 negative).  The sum of the charges on the chromium ions must be six positive.  Cr x+ + Cr x+ + Cr x+ = 6 positive  Each Cr is 2+. © 2011 Pearson Education, Inc.Chapter 7 27

Example 7.8 Determining Ionic Charge in a Compound Solution Determine the ionic charge for iron in the mineral hematite, Fe 2 O 3. Determine the ionic charge for each transition metal in the following compounds: (a)Cu 3 P 2 (b)Co 3 N 2 Practice Exercise Hematite, Fe 2 O 3 Hematite is a mineral found in nature that contains iron.

Formulas for Binary Ionic Compounds  We can determine formula of a binary ionic compound from its name.  What is the formula of iron(III) fluoride? Iron(III) has a +3 charge, Fe 3+ ; and fluoride has a –1 charge, F -.  Since the total charge must equal zero, the formula for iron(III) fluoride is FeF (– 1) = zero © 2011 Pearson Education, Inc.Chapter 7 29

Naming Binary Ionic Compounds  When naming ionic compounds, we combine the cation and anion name (drop the word “ion”), with the cation first and the anion second.  MgO is composed of one magnesium ion and one oxide ion, therefore the name is magnesium oxide.  What is the name of cinnabar, HgS? © 2011 Pearson Education, Inc.Chapter 7 30 Hg 2+ is the mercury(II) ion and S 2- is the sulfide ion, so the name is mercury(II) sulfide.

Example 7.9 Names of Binary Ionic Compounds Supply a systematic name for each of the following binary ionic compounds: (a)ZnO(b)SnF 2 Supply a systematic name for each of the following binary ionic compounds: (a) Ca 3 P 2 (b)FeCl 3 (b)Ag 2 S (d) NiO Practice Exercise

Example 7.10 Formulas of Binary Ionic Compounds Provide the formula for each of the following binary ionic compounds: (a)lithium fluoride(b)lead(II) sulfide Provide the formula for the following binary ionic compounds: (a)copper(II) iodide(b)mercury(II) oxide (b) iron (III) sulfide (d) tin (IV) nitride Practice Exercise Galena, PbS Galena is a mineral found in nature that contains lead.

Example 7.11 Predicting Formulas of Binary Ionic Compounds Predict the chemical formula for each of the following binary compounds: (a)gallium oxide(b)aluminum sulfide Predict the chemical formula for each of the following binary compounds: (a)barium chloride(b)magnesium iodide Practice Exercise

Naming Ternary Ionic Compounds  We name ternary ionic compounds like binary ionic compounds: the cation name followed by the anion name.  K 2 CO 3 is named potassium carbonate.  If we have a metal that can have than one oxidation state, we have to determine the charge on the metal.  Co(ClO 3 ) 3 is composed of cobalt(III) and chlorate ions, so its name is cobalt(III) chlorate. © 2011 Pearson Education, Inc.Chapter 7 34

Example 7.12 Determining Ionic Charge in a Compound Determine the ionic charge for iron in Fe 3 (PO 4 ) 2. Determine the ionic charge for the metal cation in each of the following compounds: (a)Ca(OH) 2 (b)Co(C 2 H 3 O 2 ) 3 Practice Exercise

Example 7.13 Names of Ternary Ionic Compound s Supply a systematic name for the following ternary ionic compounds: (a)KMnO 4 (b)Hg(NO 3 ) 2 Supply a systematic name for each of the following ternary ionic compounds. (a)BaCr 2 O 7 (b)Cu(NO 3 ) 2 Practice Exercise

Example 7.14 Formulas of Ternary Ionic Compounds Provide the formula for each of the following ternary ionic compounds: (a)nickel(II) acetate(b)iron(III) sulfate Provide the formula for each of the following ternary ionic compounds. (a)mercury(I) nitrite (b) tin(II) permanganate (c) lithium perchlorate (d) lead (IV) phosphate Practice Exercise

Example 7.15 Predicting Formulas of Ternary Ionic Compounds Predict the chemical formula for each of the following ternary ionic compounds given the formula of calcium carbonate, CaCO 3 : (a)radium carbonate(b)calcium silicate Predict the chemical formula for each of the following ternary compounds given the formula of potassium chlorate, KClO 3 : (a)potassium chlorite(b)lithium bromate Practice Exercise

Formulas for Binary Compounds  We can predict the formula of an ionic compound based on the formula of a similar compound.  What is the formula of radium carbonate given that calcium carbonate is CaCO 3 ? Radium, Ra, and calcium are both in Group 2 and will have the same ionic charge.  The formula for radium carbonate is RaCO 3. © 2011 Pearson Education, Inc.Chapter 7 39

Binary Molecular Compounds  Binary molecular compounds are composed of two nonmetal elements.  A molecule is the simplest representative particle of a binary molecular compound.  IUPAC has set the following order for writing the elements in a binary molecular compound:  C, P, N, H, S, I, Br, Cl, O, and F  Notice they are arranged according to increasing electronegativity. © 2011 Pearson Education, Inc.Chapter 7 40

Naming Binary Molecular Compounds  The first element in the compound is named first and the second element has the suffix -ide.  The number of atoms of each element must be indicated by Greek prefixes. © 2011 Pearson Education, Inc.Chapter 7 41

Molecular Compounds  Binary molecular compounds contain two elements and both are nonmetals.  Some examples of binary molecular compounds are ammonia, NH 3 ; methane, CH 4 ; carbon dioxide, CO 2 ; and tetraphosphorous trisulfide, P 4 S 3. © 2011 Pearson Education, Inc.Chapter 7 42

Naming Binary Molecular Compounds, Continued  The molecular compound P 4 S 3 is used on match tips. What is the name of P 4 S 3 ?  There are 4 P atoms, use tetra-.  There are 3 S atoms, use tri-.  The name for P 4 S 3 is tetraphosphorous trisulfide.  What is the name for N 2 O 4 ?  Dinitrogen tetraoxide © 2011 Pearson Education, Inc.Chapter 7 43

An Exception  There is one exception to the use of the Greek prefixes when naming binary molecular compounds.  If there is only one atom of the first element, the mono- is not used. The prefix mono- is always used for the second element.  CO is carbon monoxide.  XeF 6 is xenon hexafluoride. © 2011 Pearson Education, Inc.Chapter 7 44

Example 7.16 Names of Binary Molecular Compounds Give the IUPAC systematic name for each of the following binary molecular compounds: (a)IF 6 (b)Br 3 O 8 Give the IUPAC systematic name for each of the following binary molecular compounds: (a) Cl 2 O 5 (b) P 4 N 10 (c) S 3 O 8 (d) BF 3 Practice Exercise

Example 7.17 Formulas of Binary Molecular Compounds Provide the formula for each of the following binary molecular compounds: (a)diphosphorus pentasulfide(b)tetraiodine nonaoxide Provide the formula for each of the following binary molecular compounds: (a) tetraphosphorus triiodide (b)disulfur hexafluoride (b) dinitrogen pentoxide (d) oxygen heptasulfide Practice Exercise

Aqueous Acids  An aqueous solution is produced when a compound dissolves in water. It is indicated by the symbol (aq).  A binary acid is an aqueous solution of a compound containing hydrogen and one other nonmetal. HF (aq) is a binary acid.  A ternary oxyacid is an aqueous solution of a compound containing hydrogen, oxygen, and one other nonmetal. HNO 3 (aq) is a ternary oxyacid. © 2011 Pearson Education, Inc.Chapter 7 47

Binary Acids  A binary acid is an aqueous solution of a compound containing hydrogen and a nonmetal.  The formula of an acid always begins with H:  HF (aq)  Binary acids are named by using the prefix hydro- before the element stem and adding the suffix -ic acid.  HF (aq) is hydrofluoric acid.  HI (aq) is hydroiodic acid. © 2011 Pearson Education, Inc.Chapter 7 48

Example 7.18 Names of Binary Acids Binary acids are named as hydro- plus nonmetal stem plus -ic acid. Since HF(aq) contains the nonmetal fluorine, we construct the systematic name as follows: hydro + fluor + ic acid gives hydrofluoric acid. Solution Give the IUPAC systematic name for HF(aq), a binary acid. Give the IUPAC systematic name for H 2 S(aq). Practice Exercise Hydrofluoric Acid, HF Aqueous hydrofluoric acid, HF, is used to etch silicon oxide during the manufacture of computer chips.

Ternary Oxyacids  Ternary oxyacids are aqueous solutions of a compound containing hydrogen and an oxyanion.  If the acid is derived from an oxyanion ending in -ate, the suffix is changed to -ic acid.  HNO 3 (aq) is nitric acid (from NO 3 -, nitrate ion).  If the acid is derived from an oxyanion ending in -ite, the suffix is changed to -ous acid.  HNO 2 (aq) is nitrous acid (from NO 2 -, nitrite ion). © 2011 Pearson Education, Inc.Chapter 7 50

Oxyanions and Oxyacids  Below is an example of ternary oxyacid and ternary compound naming. © 2011 Pearson Education, Inc.Chapter 7 51 Ternary OxyacidTernary Compound HClO hypochlorous acidNaClO sodium hypochlorite HClO 2 chlorous acidNaClO 2 sodium chlorite HClO 3 chloric acidNaClO 3 sodium chlorate HClO 4 perchloric acidNaClO 4 sodium perchlorate

Example 7.19 Names of Ternary Oxyacids Give the IUPAC systematic name for H 3 PO 4 (aq), a ternary oxyacid. Give the IUPAC systematic name for H 3 PO 3 (aq), a ternary oxyacid. Practice Exercise

Chapter Summary  Most inorganic compounds do not contain carbon.  Binary ionic compounds are composed of a metal and a nonmetal.  Ternary ionic compounds are composed of a metal, a nonmetal, and oxygen.  Binary molecular compounds are composed of two nonmetal elements.  Acids are composed of hydrogen and a nonmetal atom or an oxyanion. © 2011 Pearson Education, Inc.Chapter 7 53

Chapter Summary, Continued  Cations are named the element plus the word ion.  Cations with more than one possible charge have their charge indicated with Roman numerals in parentheses.  Ionic compounds are named using the cation first, anion second. Then anion has the suffix -ide added.  The simplest representative unit for an ionic compound is a formula unit. © 2011 Pearson Education, Inc.Chapter 7 54

Chapter Summary, Continued  The simplest representative unit for a molecular compound is a molecule.  When naming molecular compounds, the elements are written in the order C, P, N, H, S, I, Br, Cl, O, then F.  The name of the first element is the same; the suffix -ide is added to the second element.  Greek prefixes are used to indicate the number of each atom in the formula. © 2011 Pearson Education, Inc.Chapter 7 55

Chapter Summary, Continued  An acid is an aqueous solution of a compound containing hydrogen and a nonmetal or an oxyanion.  Binary acids are named for the nonmetal atom by adding the prefix -hydro and the suffix -ic acid.  Ternary oxyacids are named by changing the -ate suffix on the oxyanion to -ic acid, or the - ite suffix on the oxyanion to -ous acid. © 2011 Pearson Education, Inc.Chapter 7 56

© 2011 Pearson Education, Inc. Which is classified as a molecular compound? a. H 2 SO 4 (aq) b. K 2 SO 3 c. Na 2 SO 4 d. SO 3

© 2011 Pearson Education, Inc. Which is the formula for the oxide ion? a. O – b. O 2– c. O 2 – d. O 2 2–

© 2011 Pearson Education, Inc. Which is the formula for the chlorate ion? a. ClO – b. ClO 2 – c. ClO 3 – d. ClO 4 –

© 2011 Pearson Education, Inc. Which is the formula for chromium(III) sulfate? a. CrSO 4 b. Cr 2 (SO 4 ) 3 c. Cr 3 (SO 4 ) 2 d. Cr 3 SO 4

© 2011 Pearson Education, Inc. Which is the formula for sulfurous acid? a. H 2 S b. H 2 SO 3 c. H 2 S 2 O 3 d. H 2 SO 4