Chapter 5 Types of Compounds Ionic Compounds Covalent Compounds LecturePLUS Timberlake1

Electronegativity (EN) Def: The strength with which an atom in a bond pulls on e-s. LecturePLUS Timberlake2

3 Covalent Bonds (bonds btwn 2 nonmetals) Nonmetals have high electronegativity values (REVIEW) Electrons are shared single bond shares 1 pair electrons double bond shares 2 pairs electrons triple bond shares 3 pairs electrons

LecturePLUS Timberlake4 Covalent Bonds Two nonmetal atoms form a covalent bond because they have less energy (are more stable!) after they bonded H  +  H H : H = H  H = H 2 hydrogen molecule

LecturePLUS Timberlake5 Learning Check Indicate whether a bond between the following would be 1) Ionic2) covalent ____A. sodium & oxygen ____B. nitrogen & oxygen ____C. phosphorus & chlorine ____D. calcium & sulfur ____E. chlorine & bromine

LecturePLUS Timberlake6 Solution Indicate whether a bond between the following would be 1) Ionic2) covalent 1A. sodium and oxygen 2B. nitrogen and oxygen 2C. phosphorus and chlorine 1D. calcium and sulfur 2E. chlorine and bromine

Types of Covalent (Molecular) Cpds 1.Elements that form diatomic molecules 2.Binary covalent compounds 3.Organic compounds/ Hydrocarbon 4.Acids & Bases (Common v. Formal Names) LecturePLUS Timberlake7

8 Diatomic Elements Elements that exist as diatomic molecules are : H 2, F 2, N 2, O 2, Cl 2, Br 2, I 2 octets          N  +  N   N ::: N  triple bond

LecturePLUS Timberlake9 Learning Check Use the name of the element to name a diatomic molecules. H 2 hydrogen N 2 nitrogen Cl 2 _______________ O 2 _______________ I 2 _______________

LecturePLUS Timberlake10 Solution Use the name of the element to name the following diatomic molecules. H 2 hydrogen N 2 nitrogen Cl 2 chlorine O 2 oxygen I 2 iodine

LecturePLUS Timberlake11 Naming Binary Covalent Compounds Two nonmetals (def of binary covalent) Name each element End the last element in -ide Add prefixes to show how many atoms of each (except when there’s only 1 atom of the 1 st element listed) Prefixes-(see Table 5.5, p 168 of text) mon1 penta5 di2hexa6 tri3hepta7 tetra4octa8

LecturePLUS Timberlake12 Learning Check Fill in the blanks to complete the following names of covalent compounds. CO carbon ______oxide CO 2 carbon _______________ PCl 3 phosphorus _______chloride CCl 4 carbon ________chloride N 2 O_____nitrogen _____oxide

LecturePLUS Timberlake13 Solution CO carbon monoxide CO 2 carbon dioxide PCl 3 phosphorus trichloride CCl 4 carbon tetrachloride N 2 Odinitrogen monoxide

LecturePLUS Timberlake14 Learning Check A.P 2 O 5 1) phosphorus oxide 2) phosphorus pentoxide 3) diphosphorus pentoxide B.Cl 2 O 7 1) dichlorine heptoxide 2) dichlorine oxide 3) chlorine heptoxide C. Cl 2 1) chlorine 2) dichlorine 3) dichloride

LecturePLUS Timberlake15 Solution A.P 2 O 5 3) diphosphorus pentoxide B.Cl 2 O 7 1) dichlorine heptoxide C. Cl 2 1) chlorine

Naming Organic Compounds Def: organic compounds contain __ atoms hooked together. (Why do you think this element can hook up with many other atoms, including itself?)

Hydrocarbons-A Type of Organic Compound Def: hydrocarbons are made of ___ & ___ They are named by the number of Carbon atoms a molecule contains. See Table 5.8, p 183

Table 5.8: Hydrocarbons CH 4 methane C 2 H 6 ethane C 3 H 8 propane C 4 H 10 butane C 5 H 12 pentane C 6 H 14 hexane C 7 H 16 heptane C 8 H 18 octane C 9 H 20 nonane C 10 H 22 decane

Common v. Formal Names Formal Names follow the rules we have learned for naming compounds. Common Names are ones that don’t follow these rules. –Ex: water=

Frequently Used Common Names Water = H 2 O Ammonia = NH 3 Common Acids & Bases

Acids & Bases (Table 5.7, p 182) ACIDS FormulaName HClhydrochloric acid H 2 SO 4 sulfuric acid H 3 PO 4 phosphoric acid HNO 3 nitric acid HC 2 H 3 O 2 acetic acid (vinegar)

Table 5.7 (cont.): BASES FormulaName NaOHsodium hydroxide KOHpotassium hydroxide NH3ammonia

LecturePLUS Timberlake23 Covalent Bonds in NH 3 Bonding pairs H  H : N : H  Lone pair of electrons

Allotropes Def: molecules of the same element that differ in structure Ex: Carbon…graphite, charcoal, Buckminsterfullerine (“bucky ball”) - see Fig ___ on p ___ of text Ex2: O 2 (oxygen) and O 3 (ozone)

Q:Why do we have to specify the number of atoms of each element in a covalent compound? A: Atoms of the same elements can combine in different ratios. Ex: C & O CO CO 2

Writing Formulas for Covalent Compounds 1. Identify it as a covalent: containing only nonmetals. 2. Determine what type of covalent it is: diatomic elementbinary hydrocarbon (ends in –ane)acid/base 3. Reverse the naming process. LecturePLUS Timberlake26

Naming Ionic Compounds Binary Ionic Ionic Compounds contain- ing Polyatomic Ions. Ionic Cpds containing Transition Metals LecturePLUS Timberlake27

PLEASE NOTE: IF YOU ARE UNABLE TO IDENTIFY IONIC & COVALENT COMPOUNDS, YOU WILL BE LOST!!! PLEASE SEE ME IMMEDIATELY TO GET CAUGHT UP. LecturePLUS Timberlake28

LecturePLUS Timberlake29 Ionic Bonding & Electronegativity Nonmetals have high EN’s. Metals have low EN’s. Bonds between a metal & a nonmetal involve transfers of e-s b/c of the big difference in EN!

Binary Ionic Compounds Binary= 2 elements Ionic= 1 metal & 1 nonmetal LecturePLUS Timberlake30

Naming Binary Ionic Compounds 1. Identify & name the 2 elements in the compound. 2. Name the cation, which is the given the name of the element. 3. Name the anion, which is given the name of the element, w/the ending changed to “–ide.” LecturePLUS Timberlake31

PRACTICE Naming Binary Ionic Compounds 1. Na║Cl 2. Na = “sodium” 3. Cl = “chloride” (full name is “sodium chloride”) LecturePLUS Timberlake32

PRACTICE Naming Binary Ionic Compounds 1. Li 2 O 2 & 3. ____║____= ______ ______ ( cation (anion (cation name) (anion name) symbol) symbol) LecturePLUS Timberlake33

MORE PRACTICE Naming Binary Ionic Compounds-p __ of I.N. 1.KF 2.CaF 2 3.Al 2 O 3 LecturePLUS Timberlake34

Naming Ionic Compounds w/ Polyatomic Ions DEF: Charged particles containing more than 1 type of atom. Ex: SO 4 2- LecturePLUS Timberlake35

Naming Ionic Compounds w/ Polyatomic Ions 1.Identify the cation & the anion. (Draw a line between the 2 ions) 2.Name the cation, then the anion (find polyatomics on Table 5.3, p 159 of text). That’s it! LecturePLUS Timberlake36

PRACTICE :Naming Ionic Compounds w/ Polyatomic Ions EX: Na 2 SO 4 ____║____= ______ ______ ( cation (anion (cation name) (anion name) symbol) symbol) LecturePLUS Timberlake37

Naming Ionic Compounds w/ Polyatomic Ions Most polyatomic ions are anions. LecturePLUS Timberlake38

A Couple of Important Exceptions w/Polyatomic Ions Important Exception #1: there are 2 cations that contain NO METALS: NH 4 + (ammonium) H 3 O + (hydronium) (this can be tricky b/c we have always identified ionic compounds because they start with a metal cation.) LecturePLUS Timberlake39

A Couple of Important Exceptions w/Polyatomic Ions Important Exception #2: Some anions contain metals. Ex: MnO 4 - = permanganate Cr 2 O 7 2- = dichromate (this can be tricky b/c anions are usually a nonmetal) LecturePLUS Timberlake40

Copy Table 5.2 into Notes LecturePLUS Timberlake41

Naming Ionic Cpds Containing Transition Metals Ex: NiO 2 1.Determine the total # of negative charges in a unit of the compound: Ex: O 2- & O 2- = 4 total - charges 2. Determine the charge on the cation that will give you 4 total + charges Ex: Ni Write the cation & anion names. Write cation with the oxidation # written as a Roman numeral in parentheses: Ex: nickel (IV) oxide LecturePLUS Timberlake42

Writing Formulas for Binary Ionic Compounds 1. Identify the ionic charge (“oxidation number”) on the cation & anion. LecturePLUS Timberlake43

Writing Formulas for Binary Ionic Compounds ELEMENTOXIDATION # Group 11+ Group 22+ Group 133+ Group 144+ or 4- Group 153- Group 162- Group 171- LecturePLUS Timberlake44

Practice Predicting Oxidation #s Li O Mg F B LecturePLUS Timberlake45

Writing Formulas for Binary Ionic Compounds 2. A compound has NO CHARGE on it, so a formula unit (the smallest ratio of cations to anions) must have equal numbers of + & - charges. (use the LCM) LecturePLUS Timberlake46

Cross-Over Method You can use this to write formulas. Take the charge on the cation and use it as the subscript on the anion Take the charge on the anion and use it as the subscript on the cation Reduce the subscripts, if necessary LecturePLUS Timberlake47

Using the LCM to Write Ionic Formulas Ex: Li & F Ex: Li & O Ex: Al & O LecturePLUS Timberlake48

ANSWERS LiF Li 2 O Al 2 O 3 LecturePLUS Timberlake49

Writing Formulas for I.Cpds Containing Polyatomic Ions Determine the cation & anion Determine the oxidation # on each ion. (oxidation #s for polyatomics are found on Table 5.2) Write a balanced formula –If there is more than 1 of an ion, use parentheses, then a subscript LecturePLUS Timberlake50

Writing Formulas for I.Cpds Containing Polyatomic Ions Ex: see Practice Problems, p Write the formula for the compound formed from the following pairs of ions a) ammonium & sulfite ions IONS: NH 4 + & SO 3 2- NH 4 + FORMULA: (NH 4 ) 2 SO 3 LecturePLUS Timberlake51

Practice Problems, cont. from p 16 2of text 3b) 3c) 3d) 4a) 4b) 4c) 4d) LecturePLUS Timberlake52

Transition Metals QUESTION: What was strange about the e- configurations of transition metals? LecturePLUS Timberlake53 ANSWER: Their d sublevels overlap with the other sublevels in the next higher main E.L.

Oxidation #s of Transition Metals The d sublevel e-s are so close to the actual valence e-s, they sometimes act like valence e-s! See Table 5.4 on p 164 of text: Common Ions of Select Transition Metals Ex: Fe 2+ & Fe 3+ Write the e- configuration LecturePLUS Timberlake54

e- Configuration for Fe Fe=26 e-s 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 6 Valence e-s=4s 2 BUT, some 3d e-s can be lost too! LecturePLUS Timberlake55

Writing Formulas for Ionic Cpds containing Transition Metals 1. Identify the cation & anion 2. Determine the oxidation #s on the cation & anion –The oxidation # of the cation is given in the name ex: Nickel (IV) = Ni 4+ –The Roman numeral is the oxidation# 3. Write a formula w/ 0 charge. LecturePLUS Timberlake56

Distillation Def: process of separating ionic & covalent compounds by heating them till the covalent compound evaporates. –The ionic compound remains in the flask –The covalent compound can be cooled & collected in a separate container. –This process is called distillation

LecturePLUS Timberlake58 Learning Check Match each set with the correct name: A. Na 2 CO 3 1) magnesium sulfite MgSO 3 2) magnesium sulfate MgSO 4 3) sodium carbonate B.Ca(HCO 3 ) 2 1) calcium carbonate CaCO 3 2) calcium phosphate Ca 3 (PO 4 ) 2 3) calcium bicarbonate

LecturePLUS Timberlake59 Solution A. Na 2 CO 3 3) sodium carbonate MgSO 3 1) magnesium sulfite MgSO 4 2) magnesium sulfate B.Ca(HCO 3 ) 2 3) calcium bicarbonate CaCO 3 1) calcium carbonate Ca 3 (PO 4 ) 2 2) calcium phosphate

LecturePLUS Timberlake60 Learning Check A. aluminum nitrate 1) AlNO 3 2) Al(NO) 3 3) Al(NO 3 ) 3 B. copper(II) nitrate 1) CuNO 3 2) Cu(NO 3 ) 2 3) Cu 2 (NO 3 ) C. Iron (III) hydroxide 1) FeOH2) Fe 3 OH3) Fe(OH) 3 D. Tin(IV) hydroxide 1) Sn(OH) 4 2) Sn(OH) 2 3) Sn 4 (OH)

LecturePLUS Timberlake61 Solution A. aluminum nitrate 3) Al(NO 3 ) 3 B. copper(II) nitrate 2) Cu(NO 3 ) 2 C. Iron (III) hydroxide 3) Fe(OH) 3 D. Tin(IV) hydroxide 1) Sn(OH) 4