Chapter 7 Chemical Formulas and Chemical Compounds Table of Contents Section 1 Chemical Names and Formulas Section 2 Oxidation Numbers Section 3 Using Chemical Formulas Section 4 Determining Chemical Formulas Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Opener #9 - Thursday, October 18, 2012 • CCl4 MgCl2 • 1. Guess the name of each of the above compounds based on the formulas written. • 2. What kind of information can you discern from the formulas? • 3. Guess which of the compounds represented is molecular and which is ionic. • Chemical formulas form the basis of the language of chemistry and reveal much information about the substances they represent. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Objectives • Explain the significance of a chemical formula. • Determine the formula of an ionic compound formed between two given ions. • Name an ionic compound given its formula. • Using prefixes, name a binary molecular compound from its formula. • Write the formula of a binary molecular compound given its name. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Visual Concepts Reading Chemical Formulas NOT NEEDED Click below to watch the Visual Concept. http://my.hrw.com/sh/hc6_003036809x/stud Visual Concept ent/ch07/sec01/vc00/hc607_01_v00fs.htm Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 7.1 Naming Ions A rose is rosa in Spanish, warda in Arabic, and julab in Hindi. To truly understand another culture, you must first learn the language used in that culture. Similarly, to understand chemistry, you must learn its language. For this you need to know how to name ions. Slide of 33 5 © Copyright Pearson Prentice Hall End Show Chapter 7 Section 1 Chemical Names and Formulas Significance of a Chemical Formula • A chemical formula indicates the relative number of atoms of each kind in a chemical compound. • For a molecular compound, the chemical formula reveals the number of atoms of each element contained in a single molecule of the compound. • example: octane — C8H18 The subscript after the C indicates that there are 8 carbon atoms in the molecule. The subscript after the H indicates that there are 18 hydrogen atoms in the molecule. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 • Hydrocarbons are molecular compounds composed only of carbon and hydrogen. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Significance of a Chemical Formula, continued • An ionic compound consists of a lattice of positive and negative ions held together by mutual attraction. • The chemical formula for an ionic compound represents one formula unit—the simplest ratio of the compound’s positive ions (cations) and its negative ions (anions). • example: aluminum sulfate — Al2(SO4)3 • Parentheses surround the polyatomic ion as a unit. The subscript 3 refers to the unit. to identify it • Note also that there is no subscript for sulfur: when there is no subscript next to an atom, the subscript is understood to be 1. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 7.1 Naming Ions > Monatomic Ions Monatomic Ions How are the charges of Group A metal and nonmetal ions related to their positions in the periodic table? Slide of 33 9 © Copyright Pearson Prentice Hall End Show 7.1 Naming Ions > Monatomic Ions Monatomic ions consist of a single atom with a positive or negative charge resulting from the loss or gain of one or more valence electrons, respectively. Slide of 33 10 © Copyright Pearson Prentice Hall End Show Chapter 7 Section 1 Chemical Names and Formulas Monatomic Ions • Many main-group elements can lose or gain electrons to form ions. • Ions formed form a single atom are known as monatomic ions. • example: To gain a noble-gas electron configuration, nitrogen gains three electrons to form N3– ions. • Some main-group elements tend to form covalent bonds instead of forming ions. • examples: carbon and silicon Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 7.1 Naming Ions > Monatomic Ions Cations When the metals in Groups 1, 2, & 13 (1A, 2A, and 3A) lose electrons, they form cations with positive charges equal to their group number. (13 also known as 3A.) Group 1 has 1+ charge (loses 1 electron) Group 2 has 2+ charge (loses 2 electrons) Aluminum in Group 13 (3A) has 3+ charge (loses 3 electrons). Slide of 33 12 © Copyright Pearson Prentice Hall End Show 7.1 Naming Ions > Monatomic Ions The names of the cations of the Group 1, 2, and 13 (1A, Group 2A, and Group 3A) metals are the same as the name of the metal, followed by the word ion or cation. Slide of 33 13 © Copyright Pearson Prentice Hall End Show Chapter 7 Section 1 Chemical Names and Formulas Monatomic Ions, continued Naming Monatomic Ions • Monatomic cations are identified simply by the element’s name. • examples: • K+ is called the potassium cation • Mg2+ is called the magnesium cation Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 7.1 Naming Ions > Monatomic Ions These elements have ionic charges that can be obtained from their group numbers. Slide of 33 15 © Copyright Pearson Prentice Hall End Show 7.1 Naming Ions > Monatomic Ions Group 15, 16, & 17 (5A, 6A, 7A) elements form anions. Slide of 33 16 © Copyright Pearson Prentice Hall End Show 7.1 Naming Ions > Monatomic Ions Anions The charge of any ion of a nonmetal Group is determined by subtracting 8 from the valence electron number. (example Group 15 would have 5 valence electrons, so 5-8 = -3, so charge is -3 for Group 15. Similarly charge for Group 16 is -2 and Group 17 is -1. Anion names start with the stem of the element name and end in -ide. Slide of 33 17 © Copyright Pearson Prentice Hall End Show Chapter 7 Section 1 Chemical Names and Formulas Monatomic Ions, continued Naming Monatomic Ions • For monatomic anions, the ending of the element’s name is dropped, and the ending -ide is added to the root name. • examples: • F– is called the fluoride anion • N3– is called the nitride anion • Group 14 share electrons in covalent bonds. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 7.1 Naming Ions > Monatomic Ions Slide of 33 19 © Copyright Pearson Prentice Hall End Show Chapter 7 Section 1 Chemical Names and Formulas Common Monatomic Ions Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Visual Concepts Naming Monatomic Ions Click below to watch the Visual Concept. http://my.hrw.com/sh/hc6_003036809x/stu Visual Concept dent/ch07/sec01/vc01/hc607_01_v01fs.ht m Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 7.1 Naming Ions > Monatomic Ions Ions of Transition Metals How are the charges of some transition metal ions determined? Slide of 33 22 © Copyright Pearson Prentice Hall End Show 7.1 Naming Ions > Monatomic Ions The charges of the cations of many transition metal ions must be determined from the number of electrons lost. The d-block (transition metals) form 2 or more cations with different charges. Example Copper, Cu may be 1+ or 2+ depending upon if it loses 1 or 2 electrons. Slide of 33 23 © Copyright Pearson Prentice Hall End Show 7.1 Naming Ions > Monatomic Ions These colorful solutions contain the transition metal ions Co3+, Cr3+, Fe3+, Ni2+, and Mn2+. Slide of 33 24 © Copyright Pearson Prentice Hall End Show 7.1 Naming Ions > Monatomic Ions Many transition metal compounds are colored and can be used as pigments. Slide of 33 25 © Copyright Pearson Prentice Hall End Show 7.1 Naming Ions > Monatomic Ions Two methods are used to name the ions of transition metals. • The Stock system • The classical method Slide of 33 26 © Copyright Pearson Prentice Hall End Show 7.1 Naming Ions > Monatomic Ions In the Stock system, a Roman numeral in parentheses is placed after the name of the element to indicate the numerical value of the charge. Slide of 33 27 © Copyright Pearson Prentice Hall End Show 7.1 Naming Ions > Monatomic Ions In an older less, useful method, the classical name of the element is used to form the root name for the element. Slide of 33 28 © Copyright Pearson Prentice Hall End Show 7.1 Naming Ions > Monatomic Ions Slide of 33 29 © Copyright Pearson Prentice Hall End Show Chapter 7 Section 1 Chemical Names and Formulas Common Monatomic Ions Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 1.1 Conceptual Problem 9.1 Conceptual problem 1.1 Slide of 33 © Copyright Pearson Prentice Hall End Show 1.1 Conceptual Problem 9.1 Slide of 33 © Copyright Pearson Prentice Hall End Show 1.1 Conceptual Problem 9.1 Slide of 33 © Copyright Pearson Prentice Hall End Show Practice Problems for Conceptual Problem 9.1 CLICK HERE FOR ACTIVITY Practice Problems For Conceptual Problem 9.1 CLICK HERE FOR ACTIVITY Problem-Solving 9.1 Solve Problem 1 with the help of an interactive guided tutorial. Slide of 33 © Copyright Pearson Prentice Hall End Show 7.1 Naming and Writing Formulas for Ionic Compounds A recipe is a formula for the sauce—a complete list of ingredients and their proportions. Chemistry also uses formulas. Once you know the rules, you can write the formula for any chemical compound. Slide of 33 35 © Copyright Pearson Prentice Hall End Show Chapter 7 Section 1 Chemical Names and Formulas Binary Ionic Compounds • Compounds composed of two elements are known as binary compounds. • In a binary ionic compound, the total numbers of positive charges and negative charges must be equal. • To name any binary ionic compound, place the cation name first, followed by the anion name. • The formula for a binary ionic compound can be written given the identities of the compound’s ions. • example: magnesium bromide Ions combined: Mg2+, Br–, Br– Chemical formula: MgBr2 Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Binary Ionic Compounds, continued • A general rule to use when determining the formula for a binary ionic compound is “crossing over” to balance charges between ions. • example: aluminum oxide 1) Write the symbols for the ions. Al3+ O2– 2) Cross over the charges by using the absolute value of each ion’s charge as the subscript for the other ion. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Binary Ionic Compounds, continued • example: aluminum oxide, continued 3) Check the combined positive and negative charges to see if they are equal. (2 3+) + (3 2) = 0 The correct formula is Al2O3 Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Writing the Formula of an Ionic Compound Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Naming Binary Ionic Compounds, continued Sample Problem A Write the formulas for the binary ionic compounds formed between the following elements: a. zinc and iodine b. zinc and sulfur Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Naming Binary Ionic Compounds, continued Sample Problem A Solution Write the symbols for the ions side by side. Write the cation first. a. Zn2+ I– b. Zn2+ S2– Cross over the charges to give subscripts. a. b. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Naming Binary Ionic Compounds, continued Sample Problem A Solution, continued Check the subscripts and divide them by their largest common factor to give the smallest possible wholenumber ratio of ions. a. The subscripts give equal total charges of 1 2+ = 2+ and 2 1– = 2–. The largest common factor of the subscripts is 1. The smallest possible whole-number ratio of ions in the compound is 1:2. The formula is ZnI . 2 Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Naming Binary Ionic Compounds, continued Sample Problem A Solution, continued b. The subscripts give equal total charges of 2 2+ = 4+ and 2 2 = 4. The largest common factor of the subscripts is 2. The smallest whole-number ratio of ions in the compound is 1:1. The formula is ZnS. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Naming Binary Ionic Compounds • The nomenclature, or naming system, or binary ionic compounds involves combining the names of the compound’s positive and negative ions. • The name of the cation is given first, followed by the name of the anion: • example: Al2O3 — aluminum oxide • For most simple ionic compounds, the ratio of the ions is not given in the compound’s name, because it is understood based on the relative charges of the compound’s ions. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Visual Concepts Naming Ionic Compounds Click below to watch the Visual Concept. http://my.hrw.com/sh/hc6_0030368 Visual Concept 09x/student/ch07/sec01/vc02/hc607 _01_v02fs.htm Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Naming Binary Ionic Compounds, continued The Stock System of Nomenclature • Some elements such as iron, form two or more cations with different charges. • To distinguish the ions formed by such elements, scientists use the Stock system of nomenclature. • The system uses a Roman numeral to indicate an ion’s charge. • examples: Fe2+ iron(II) Fe3+ iron(III) Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Visual Concepts Naming Compounds Using the Stock System Click below to watch the Visual Concept. http://my.hrw.com/sh/hc6_003036809x/stud Visual Concept ent/ch07/sec01/vc03/hc607_01_v03fs.htm Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Naming Binary Ionic Compounds, continued The Stock System of Nomenclature, continued Sample Problem B Write the formula and give the name for the compound formed by the ions Cr3+ and F–. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Naming Binary Ionic Compounds, continued The Stock System of Nomenclature, continued Sample Problem B Solution Write the symbols for the ions side by side. Write the cation first. Cr3+ F– Cross over the charges to give subscripts. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Naming Binary Ionic Compounds, continued The Stock System of Nomenclature, continued Sample Problem B Solution, continued The subscripts give charges of 1 3+ = 3+ and 3 1 = 3. The largest common factor of the subscripts is 1, so the smallest whole number ratio of the ions is 1:3. The formula is CrF3. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Naming Binary Ionic Compounds, continued The Stock System of Nomenclature, continued Sample Problem B Solution, continued Chromium forms more than one ion, so the name of the 3+ chromium ion must be followed by a Roman numeral indicating its charge. The compound’s name is chromium(III) fluoride. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Naming and Writing Formulas for Ionic Compounds > Simulation 9.11 CLICK HERE FOR ACTIVITY ACTIVITY INCLUDES THE FOLLOWING: Slide of 29 52 © Copyright Pearson Prentice Hall End Show Chapter 7 Practice Problems pg. 223 • Complete the above problems before going to next page. Ask questions if you do not understand or miss the problems!!! Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 ANSWERS to pg. 223 • Ask me if you do not understand. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Practice Problems pg. 225 • Complete all problems above before going to the next page. ASK QUESTIONS if you do not understand! Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 ANSWERS pg. 225 Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 7.1 Naming Ions > Polyatomic Ions Polyatomic Ions What are the two endings of the names of most polyatomic ions? Slide of 33 57 © Copyright Pearson Prentice Hall End Show 7.1 Naming Ions > Polyatomic Ions Some ions, called polyatomic ions, are composed of more than one atom. The names of most polyatomic anions end in -ite or -ate. Slide of 33 58 © Copyright Pearson Prentice Hall End Show Chapter 7 Section 1 Chemical Names and Formulas Naming Binary Ionic Compounds, continued Compounds Containing Polyatomic Ions • Many common polyatomic ions are oxyanions— polyatomic ions that contain oxygen. • Some elements can combine with oxygen to form more than one type of oxyanion. • example: nitrogen can form or . • The name of the ion with the greater number of oxygen atoms ends in -ate. The name of the ion with the smaller number of oxygen atoms ends in -ite. nitrate nitrite Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Naming Binary Ionic Compounds, continued Compounds Containing Polyatomic Ions, continued • Some elements can form more than two types of oxyanions. • example: chlorine can form , , or • In this case, an anion that has one fewer oxygen atom than the -ite anion has is given the prefix hypo-. • An anion that has one more oxygen atom than the -ate anion has is given the prefix per-. hypochlorite chlorite chlorate Chapter menu perchlorate Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 7.1 Naming Ions > Polyatomic Ions These models show the structures of four common polyatomic ions. Slide of 33 61 © Copyright Pearson Prentice Hall End Show 7.1 Naming Ions > Polyatomic Ions Sodium hydrogen carbonate can relieve an upset stomach. Slide of 33 62 © Copyright Pearson Prentice Hall End Show 7.1 Naming Ions > Polyatomic Ions HCO3–, HPO42–, and H2PO4– ions in your blood are critical for your health. Slide of 33 63 © Copyright Pearson Prentice Hall End Show 7.1 Naming Ions > Polyatomic Ions Fertilizers contain HPO42– and H2PO4– ions. Slide of 33 64 © Copyright Pearson Prentice Hall End Show 7.1 Naming Ions > Polyatomic Ions Names and Formulas of Some Common Polyatomic Ions Slide of 33 65 © Copyright Pearson Prentice Hall End Show Chapter 7 Section 1 Chemical Names and Formulas Polyatomic Ions Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Naming Compounds with Polyatomic Ions Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 7.1 Naming and Writing Formulas for Ionic Compounds > Compounds With Polyatomic Ions Naming Compounds with Polyatomic Ions To name a compound containing a polyatomic ion, state the cation first and then the anion, just as you did in naming binary ionic compounds. Slide of 29 68 © Copyright Pearson Prentice Hall End Show 7.1 Naming and Writing Formulas for Ionic Compounds > Compounds With Polyatomic Ions Sodium hypochlorite (NaClO) is used as a disinfectant for swimming pools. The metallic cation in this compound is sodium (Na+) so the polyatomic ion must be ClO–. Slide of 29 69 © Copyright Pearson Prentice Hall End Show Naming and Writing Formulas for Ionic Compounds > Simulation 9 CLICK HERE FOR ACTIVITY ACTIVITY INCLUDES THE FOLLOWING: Slide of 29 70 © Copyright Pearson Prentice Hall End Show Chapter 7 Section 1 Chemical Names and Formulas Understanding Formulas for Polyatomic Ionic Compounds Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Visual Concepts Naming Compounds Containing Polyatomic Ions Click below to watch the Visual Concept. http://my.hrw.com/sh/hc6_003036809x/stude Visual Concept nt/ch07/sec01/vc04/hc607_01_v04fs.htm Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 7.1 Naming and Writing Formulas for Ionic Compounds > Compounds With Polyatomic Ions Compounds with Polyatomic Ions How do you write the formulas and names of compounds containing polyatomic ions? Slide of 29 73 © Copyright Pearson Prentice Hall End Show 7.1 Naming and Writing Formulas for Ionic Compounds > Compounds With Polyatomic Ions Write the symbol for the cation followed by the formula for the polyatomic ion and balance the charges. Slide of 29 74 © Copyright Pearson Prentice Hall End Show 7.1 Naming and Writing Formulas for Ionic Compounds > Compounds With Polyatomic Ions For example, calcium nitrate is composed of a calcium cation (Ca2+) and a polyatomic nitrate anion (NO3–). In calcium nitrate, two nitrate anions, each with a 1– charge, are needed to balance the 2+ charge of each calcium cation. The formula for calcium nitrate is Ca(NO3)2. Slide of 29 75 © Copyright Pearson Prentice Hall End Show Practice Problems for Conceptual Problem 9.3 Practice Problems For Conceptual Problem 9.3 CLICK HERE FOR ACTIVITY Problem-Solving 9.12 Solve Problem 12 with the help of an interactive guided tutorial. Slide of 33 © Copyright Pearson Prentice Hall End Show Naming and Writing Formulas for Ionic Compounds > Simulation 9 Simulation 9 Simulate combining ions and deriving the chemical formulas for several ionic compounds. CLICK BELOW TO SEE SIMULATION ACTIVITY. ACTIVITY - CLICK HERE Slide of 29 77 © Copyright Pearson Prentice Hall End Show Chapter 7 Section 1 Chemical Names and Formulas Naming Binary Ionic Compounds, continued Compounds Containing Polyatomic Ions, continued Sample Problem C Write the formula for tin(IV) sulfate. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Naming Binary Ionic Compounds, continued Compounds Containing Polyatomic Ions, continued Sample Problem C Solution Write the symbols for the ions side by side. Write the cation first. Cross over the charges to give subscripts. Add parentheses around the polyatomic ion if necessary. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Naming Binary Ionic Compounds, continued Compounds Containing Polyatomic Ions, continued Sample Problem C Solution, continued The total positive charge is 2 4+ = 8+. The total negative charge is 4 2 = 8. The largest common factor of the subscripts is 2, so the smallest whole-number ratio of ions in the compound is 1:2. The correct formula is therefore Sn(SO4)2. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 9.2 Conceptual Problem 9.2 TRY THESE WITHOUT WRITING DOWN Note if ratio can be simplified to lower terms, it will be reduced. Example - a ratio of 2:2 will reduce to 1:1. Slide of 29 © Copyright Pearson Prentice Hall End Show Practice Problems for Conceptual Problem 9.2 Sample Problems For Conceptual Problem 9.2 SEE IF YOU CAN GET THESE CORRECT BEFORE DOING THE ADDITIONAL PRACTICE PROBLEMS - NOTE THE CLICK BELOW. CLICK HERE FOR ACTIVITY Problem Solving 9.11 Solve Problem 11 with the help of an interactive guided tutorial. Slide of 33 © Copyright Pearson Prentice Hall End Show Chapter 7 Practice Problems pg. 227 Complete all of these before going to next slide! Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 ANSWERS pg. 227 Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 7.1 Naming and Writing Formulas for Molecular Compounds > Naming Binary Molecular Compounds Naming Binary Molecular Compounds What does a prefix in the name of a binary molecular compound tell you about the compound’s composition? Slide of 15 85 © Copyright Pearson Prentice Hall End Show Chapter 7 Section 1 Chemical Names and Formulas Naming Binary Molecular Compounds • Unlike ionic compounds, molecular compounds are composed of individual covalently bonded units, or molecules. • As with ionic compounds, there is also a Stock system for naming molecular compounds. • The old system of naming molecular compounds is based on the use of prefixes. • examples: CCl4 — carbon tetrachloride (tetra- = 4) CO — carbon monoxide (mon- = 1) CO2 — carbon dioxide (di- = 2) Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 7.1 Naming and Writing Formulas for Molecular Compounds > Naming Binary Molecular Compounds A prefix in the name of a binary molecular compound tells how many atoms of an element are present in each molecule of the compound. Slide of 15 87 © Copyright Pearson Prentice Hall End Show Chapter 7 Section 1 Chemical Names and Formulas Prefixes for Naming Covalent Compounds Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Visual Concepts Naming Covalently-Bonded Compounds Click below to watch the Visual Concept. http://my.hrw.com/sh/hc6_003036809x/stud Visual Concept ent/ch07/sec01/vc05/hc607_01_v05fs.htm Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Visual Concepts Naming Compounds Using Numerical Prefixes Click below to watch the Visual Concept. http://my.hrw.com/sh/hc6_003036809x/student Visual Concept /ch07/sec01/vc06/hc607_01_v06fs.htm Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Prefix Method for COVALENT • Prefix method: 1)The element that has the smaller group number is usually given first. If both are in same group, then the element whose period number is greater goes first. The element is given a prefix only if greater than one. Do not use monoon the first element. 2)The 2nd element is named by combining a prefix and the root name of the element ending in –ide. 3)The o or a at the end of a prefix is usually dropped when the word following the prefix begins with another vowel. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Naming Binary Molecular Compounds, continued Sample Problem D a. Give the name for As2O5. b. Write the formula for oxygen difluoride. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Naming Binary Molecular Compounds, continued Sample Problem D Solution a. A molecule of the compound contains two arsenic atoms, so the first word in the name is diarsenic. The five oxygen atoms are indicated by adding the prefix pent- to the word oxide. The complete name is diarsenic pentoxide. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Naming Binary Molecular Compounds, continued Sample Problem D Solution, continued b. Oxygen is first in the name because it is less electronegative than fluorine. Because there is no prefix, there must be only one oxygen atom. The prefix di- in difluoride shows that there are two fluorine atoms in the molecule. The formula is OF2. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 › • DO NOT GO TO THE NEXT PAGE UNTIL YOU ARE DONE WITH THE PROBLEMS. ASK FOR HELP IF NEEDED. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 ANSWERS pg. 229 ANSWERS pg. 229 Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Chemical Names and Formulas Covalent-Network Compounds • Some covalent compounds do not consist of individual molecules. • Instead, each atom is joined to all its neighbors in a covalently bonded, three-dimensional network. • Subscripts in a formula for covalent-network compound indicate smallest whole-number ratios of the atoms in the compound. • examples: SiC, silicon carbide SiO2, silicon dioxide Si3N4, trisilicon tetranitride. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 7.1 QUESTION - use points later as needed to incorporate into other ppt • not using the next slides right now - may incorporate some of them at later date for 7.1 Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 7.1 Section Quiz. Assess students’ understanding of the concepts in Section 7.1. Continue to: -or- Launch: Section Quiz Slide of 15 © Copyright Pearson Prentice Hall End Show 7.1 Section Quiz. 1. Which of the following compounds is named INCORRECTLY? a. CS2, carbon disulfide b. BCl3, boron trichloride c. IF7, iodine heptafluoride d. PCl5, phosphorus hexachloride Slide of 29 © Copyright Pearson Prentice Hall End Show 7.1 Section Quiz. 2. Which of the following molecular compounds is named INCORRECTLY? a. SbCl3, antimony trichloride b. C2O5, dicarbon pentoxide c. CF4, carbon tetrafluoride d. H3As, hydrogen arsenide Slide of 29 © Copyright Pearson Prentice Hall End Show 7.1 Section Quiz. 3. The correct formula for tetraphosphorus trisulfide is a. P3S4 b. S3P4 c. P4S3 d. S4P3 Slide of 29 © Copyright Pearson Prentice Hall End Show 7.1 Section Quiz 4. Which of the following are positively charged polyatomic ions? a. (I) ammonium ion b. (II) perchlorate ion c. (III) ferric ion a. I only b. II only c. III only d. I and III Slide of 33 © Copyright Pearson Prentice Hall End Show 7.1 Section Quiz 5. If the name of an ion ends in -ite or -ate, the ion is a a. polyatomic cation. b. polyatomic anion. c. transition metal cation. d. monatomic anion. Slide of 33 © Copyright Pearson Prentice Hall End Show 7.1 Section Quiz 6. The correct name for CrCl3 is a. chromium chlorine. b. chromium(III) chloride. c. monochromium trichloride. d. chromium(III) trichloride. Slide of 29 © Copyright Pearson Prentice Hall End Show 7.1 Section Quiz 7. What is the correct formula for strontium nitride? a. Sr3N2 b. SrN2 c. Sr2N3 d. Sr3N Slide of 29 © Copyright Pearson Prentice Hall End Show 7.1 Section Quiz 8. Which one of the following compounds is named correctly? a. sodium chlorite, NaClO b. potassium nitrate, KNO2 c. sodium acetate, NaC2H3O2 d. lithium sulfate, Li2SO3 Slide of 29 © Copyright Pearson Prentice Hall End Show 7.1 Naming and Writing Formulas for Acids and Bases Some ants can give painful stings when threatened or disturbed. Certain ant species called formicines have poison glands that produce venom containing formic acid. You will learn the names and formulas of some important acids such as formic acid. Slide of 33 108 © Copyright Pearson Prentice Hall End Show 7.1 Naming and Writing Formulas for Acids and Bases > Naming Acids An acid is a compound that contains one or more hydrogen atoms and produces hydrogen ions (H+) when dissolved in water. Acids have various uses. Slide of 19 109 © Copyright Pearson Prentice Hall End Show Chapter 7 Section 1 Chemical Names and Formulas Acids and Salts • Most acids used in the laboratory are either binary acids or oxyacids. • Binary acids are acids that consist of two elements, usually hydrogen and a halogen. • Oxyacids are acids that contain hydrogen, oxygen, and a third element (usually a nonmetal). Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 7.1 Naming and Writing Formulas for Acids and Bases > Naming Acids Naming Acids What are the three rules for naming acids? Slide of 19 111 © Copyright Pearson Prentice Hall End Show 7.1 Naming and Writing Formulas for Acids and Bases > Naming Acids Three rules can help you name an acid with the general formula HnX. When 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. Slide of 19 112 © Copyright Pearson Prentice Hall End Show 7.1 Naming and Writing Formulas for Acids and Bases > Naming Acids 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. Slide of 19 113 © Copyright Pearson Prentice Hall End Show 7.1 Naming and Writing Formulas for Acids and Bases > Naming Acids 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. Slide of 19 114 © Copyright Pearson Prentice Hall End Show 7.1 Naming and Writing Formulas for Acids and Bases > Naming Acids A Summary of the Three Rules for Naming Acids. Slide of 19 115 © Copyright Pearson Prentice Hall End Show Chapter 7 Visual Concepts Prefixes and Suffixes for Oxyanions and Related Acids Click below to watch the Visual Concept. http://my.hrw.com/sh/hc6_003036809 Visual Concept x/student/ch07/sec01/vc10/hc607_01_ v10fs.htm Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 9.3 Naming and Writing Formulas for Molecular Compounds One milligram of gold is worth only about one cent, but one kilogram of gold is worth approximately $12,500. The correct prefix ( milli- or kilo-) makes quite a difference! Prefixes are important in chemistry, too. The prefixes in the name of a binary molecular compound tell you its composition. Slide of 33 117 © Copyright Pearson Prentice Hall End Show 9.3 Naming and Writing Formulas for Molecular Compounds > Naming Binary Molecular Compounds Carbon and oxygen combine to form carbon monoxide (CO) and carbon dioxide (CO2), but these two invisible gases are very different. Slide of 15 118 © Copyright Pearson Prentice Hall End Show 9.3 Naming and Writing Formulas for Molecular Compounds > Naming Binary Molecular Compounds Sitting in a room with small amounts of CO2 in the air would not present any problems. If the same amount of CO were in the room, you could die of asphyxiation. A naming system that distinguishes between these two compounds is needed. Slide of 15 119 © Copyright Pearson Prentice Hall End Show 9.3 Naming and Writing Formulas for Molecular Compounds > Naming Binary Molecular Compounds A prefix in the name of a binary molecular compound tells how many atoms of an element are present in each molecule of the compound. Slide of 15 120 © Copyright Pearson Prentice Hall End Show 9.3 Naming and Writing Formulas for Molecular Compounds > Naming Binary Molecular Compounds Some guidelines for naming binary molecular compounds: • Name the elements in the order listed in the formula. • Use prefixes to indicate the number of each kind of atom. Slide of 15 121 © Copyright Pearson Prentice Hall End Show 9.3 Naming and Writing Formulas for Molecular Compounds > Naming Binary Molecular Compounds • Omit the prefix mono- when the formula contains only one atom of the first element in the name. • The suffix of the name of the second element is -ide. Slide of 15 122 © Copyright Pearson Prentice Hall End Show 9.3 Naming and Writing Formulas for Molecular Compounds > Writing Formulas for Binary Molecular Compounds Writing Formulas for Binary Molecular Compounds How do you write the formula for a binary molecular compound? Slide of 15 123 © Copyright Pearson Prentice Hall End Show 9.3 Naming and Writing Formulas for Molecular Compounds > Writing Formulas for Binary Molecular Compounds Use the prefixes in the name to tell you the subscript of each element in the formula. Then write the correct symbols for the two elements with the appropriate subscripts. Slide of 15 124 © Copyright Pearson Prentice Hall End Show 9.3 Naming and Writing Formulas for Molecular Compounds > Writing Formulas for Binary Molecular Compounds Silicon carbide is a hard material like diamond. The name silicon carbide has no prefixes, so the subscripts of silicon and carbon must be one. Thus, the formula for silicon carbide is SiC. Slide of 15 125 © Copyright Pearson Prentice Hall End Show 9.1 Section Quiz. Assess students’ understanding of the concepts in Section 9.1. Continue to: -or- Launch: Section Quiz Slide of @@ © Copyright Pearson Prentice Hall End Show 9.1 Section Quiz. 1. When metals from groups 1A, 2A, and 3A form cations, the charge on the ion is equal to a. 8 minus the group number. b. the group number minus 8. c. the period number. d. the group number. Slide of 33 © Copyright Pearson Prentice Hall End Show 9.2 section Quiz. Assess students’ understanding of the concepts in Section 9.2. Continue to: -or- Launch: Section Quiz Slide of 29 © Copyright Pearson Prentice Hall End Show Chapter 7 Section 1 Chemical Names and Formulas Acids and Salts, continued • In the laboratory, the term acid usually refers to a solution in water of an acid compound rather than the acid itself. • example: hydrochloric acid refers to a water solution of the molecular compound hydrogen chloride, HCl • Many polyatomic ions are produced by the loss of hydrogen ions from oxyacids. • examples: sulfuric acid H2SO4 sulfate nitric acid HNO3 nitrate phosphoric acid H3PO4 phosphate Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Visual Concepts Naming Binary Acids Click below to watch the Visual Concept. http://my.hrw.com/sh/hc6_003036809x/stu Visual Concept dent/ch07/sec01/vc07/hc607_01_v07fs.htm Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Visual Concepts Naming Oxyacids Click below to watch the Visual Concept. http://my.hrw.com/sh/hc6_003036809x/student/ch Visual Concept 07/sec01/vc08/hc607_01_v08fs.htm Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 OTHER EXAMPLES - add roots • • • • • • H2SO3 - sulfurous acid (coming from sulfite) HClO3 - chloric acid HClO2 - chlorous acid HClO - hypochlorous acid H2S - hydrosulfuric acid HClO4 - perchloric acid Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 7.1 Naming and Writing Formulas for Acids and Bases > Writing Formulas for Acids Writing Formulas for Acids How are the formulas of acids determined? Slide of 19 133 © Copyright Pearson Prentice Hall End Show 7.1 Naming and Writing Formulas for Acids and Bases > Writing Formulas for Acids Use the rules for writing the names of acids in reverse to write the formulas for acids. What is the formula for hydrobromic acid? Following Rule 1, hydrobromic acid (hydroprefix and -ic suffix) must be a combination of hydrogen ion (H+) and bromide ion (Br–). The formula of hydrobromic acid is HBr. Slide of 19 134 © Copyright Pearson Prentice Hall End Show 7.1 Naming and Writing Formulas for Acids and Bases > Writing Formulas for Acids Slide of 19 135 © Copyright Pearson Prentice Hall End Show Chapter 7 Section 1 Chemical Names and Formulas Acids and Salts, continued • An ionic compound composed of a cation and the anion from an acid is often referred to as a salt. • examples: • Table salt, NaCl, contains the anion from hydrochloric acid, HCl. • Calcium sulfate, CaSO4, is a salt containing the anion from sulfuric acid, H2SO4. • The bicarbonate ion, carbonic acid, H2CO3. , comes from Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Visual Concepts Salt Click below to watch the Visual Concept. http://my.hrw.com/sh/hc6_003036809x/student/c Visual Concept h07/sec01/vc09/hc607_01_v09fs.htm Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section Review pg. 231 • Answer questions #2, 3, and 4 in your notes before going to next page.. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Answers pg. 231 • Be sure you answered these on your own first. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 7.1 Naming and Writing Formulas for Acids and Bases > Names and Formulas for Bases Names and Formulas for Bases How are bases named? Slide of 19 140 © Copyright Pearson Prentice Hall End Show 7.1 Naming and Writing Formulas for Acids and Bases > Names and Formulas for Bases Bases are named in the same way as other ionic compounds—the name of the cation is followed by the name of the anion. For example, aluminum hydroxide consists of the aluminum cation (Al3+) and the hydroxide anion (OH–). The formula for aluminum hydroxide is Al(OH)3. Slide of 19 141 © Copyright Pearson Prentice Hall End Show Section Assessment Test yourself on the concepts in Section 7.1. Continue to: Launch: -or- Section Quiz Slide of 19 © Copyright Pearson Prentice Hall End Show 7.1 Section Quiz 1. The name for H2S(aq) is a) sulfuric acid. b) hydrosulfuric acid. c) sulfurous acid. d) hydrosulfurous acid. Slide of 19 © Copyright Pearson Prentice Hall End Show 7.1 Section Quiz 2. The chemical formula for chlorous acid is a) HClO2. b) HClO3. c) HClO4. d) HCl. Slide of 19 © Copyright Pearson Prentice Hall End Show 7.1 Section Quiz 3. The correct chemical name for NH4OH is a) nitrogen tetrahydrogen hydroxide. b) nitrogen pentahydrogen oxide. c) ammonium oxyhydride. d) ammonium hydroxide. Slide of 19 © Copyright Pearson Prentice Hall End Show Online Self-Check Quiz Complete the online Quiz and record answers. Ask if you have any questions about your answers. click here for online Quiz 7.1 (10 questions) You must be in the “Play mode” for the slideshow for hyperlink to work. Slide of 25 © Copyright Pearson Prentice Hall End Show VIDEOS FOR ADDITIONAL INSTRUCTION Additional Videos for Section 7.1: Chemical Names and Formulas Elements and Compounds Acid and Base Properties Salts Slide of 28 © Copyright Pearson Prentice Hall End Show 7.1 End of 7.1 Notes and Practice Problems Slide of 28 © Copyright Pearson Prentice Hall End Show