LecturePLUS Timberlake1 ChemI/IH:Chapter8 Covalent Bonding (click for video)Covalent Bonding (click for video) Def: bonds in which electrons are SHARED btwn 2 or more nonmetals Nonmetals have high EN (electronegativity) values so electrons must be shared Compounds w/covalent bonds are called molecular compounds. We will learn about 4 types of molecular cpds.

1. Acids Acids are covalent compounds that act like ionic compounds. They have H+ as the “cation”. LecturePLUS Timberlake2

Acids There are 3 types of acids. They are named based on the type of ANION they contain: 1.Anion = element 2.Anion = polyatomic ion that ends in “ate” 3.Anion = polyatomic ion that ends in “ite” LecturePLUS Timberlake3

Acids 1. If anion is an element, name of acid is “hydro____ic acid” where blank is filled with root of element name Ex: HCl LecturePLUS Timberlake4 Hydrochloric acid

Acids 2. If anion is a polyatomic ion that ends in “-ate”, name of acid is “____ic acid” where blank is filled with root of polyatomic ion name Ex: HClO 3 LecturePLUS Timberlake5 chloric acidClO 3 = “chlorate”

Acids 3. If anion is a polyatomic ion that ends in “-ite”, name of acid is “____ous acid” where blank is filled with root of element name Ex: HClO 2 LecturePLUS Timberlake6 chlorous acidClO 2 = “chlorite”

Acids, Summary (copy on P. Table) LecturePLUS Timberlake7 Type of Anion Naming ruleExample ElementHydro___ic acidHCl: hydrochloric acid Polyatomic “-ate” ____ic acidHClO 4 : perchloric acid Polyatomic “-ite” ____ous acidHClO: hypochlorous acid

LecturePLUS Timberlake8 Covalent Bonding By sharing e-s, atoms obtain NGC, which makes them more stable than they were by themselves. H  +  H H : H = H  H = H 2 hydrogen molecule

Covalent Bonding single bond shares 1 pair electrons- ex:H 2 double bond shares 2 pairs electron-ex:O 2 triple bond shares 3 pairs electrons-ex: N 2 LecturePLUS Timberlake9

10 Learning Check (DON’T COPY) Indicate whether a bond between the following would be (I) Ionic OR (C) covalent ____A. sodium & oxygen ____B. nitrogen & oxygen ____C. phosphorus & chlorine ____D. calcium & sulfur ____E. chlorine & bromine

LecturePLUS Timberlake11 Solution (DON’T COPY) Indicate whether a bond between the following would be (I) Ionic OR (C) covalent IA. sodium and oxygen CB. nitrogen and oxygen CC. phosphorus and chlorine ID. calcium and sulfur CE. chlorine and bromine

LecturePLUS Timberlake12 2. Diatomic Elements Elements that exist as atom pairs H 2, O 2, N 2, Cl 2, Br 2, I 2, F 2, They are given the name of the element. octets          N  +  N   N ::: N   triple bond

LecturePLUS Timberlake13 Learning Check (DON’T COPY) Use the name of the element to name a diatomic molecules. H 2 hydrogen N 2 nitrogen Cl 2 _______________ O 2 _______________ I 2 _______________

LecturePLUS Timberlake14 Solution (COPY) 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 Timberlake15 3. Binary Covalent Compounds Two nonmetals (def of binary covalent) 1.Name each element 2.End the last element in -ide 3.Add prefixes to show how many atoms of each (except when there’s only 1 atom of the 1 st element listed) PREFIXES-COPY ONTO YOUR P. TABLE mono1 hexa6 di2hepta7 tri3octa8 tetra4nona9 penta5deca10

LecturePLUS Timberlake16 Learning Check (DON’T COPY) 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 Timberlake17 Solution (COPY!) CO carbon monoxide CO 2 carbon dioxide PCl 3 phosphorus trichloride CCl 4 carbon tetrachloride N 2 Odinitrogen monoxide

LecturePLUS Timberlake18 Learning Check (DON’T COPY) 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 Timberlake19 Solution (DON’T COPY) A.P 2 O 5 3) diphosphorus pentoxide B.Cl 2 O 7 1) dichlorine heptoxide C. Cl 2 1) chlorine

4. Hydrocarbons-A Type of Binary Covalent Compound Def: hydrocarbons are made of hydrogen & carbon They are named by the number of carbon atoms a molecule contains. They are important as fuels.

Hydrocarbons The table below lists only hydrocarbons w/single bonds The names all end w/ “ane” (COPY ONTO YOUR P. TABLE) CH 4 methaneC 6 H 14 hexane C 2 H 6 ethaneC 7 H 16 heptane C 3 H 8 propaneC 8 H 18 octane C 4 H 10 butaneC 9 H 20 nonane C 5 H 12 pentaneC 10 H 22 decane

Writing Formulas for Molecular Compounds 1. Analyze the name of the compound 2. Identify the type of compound (diatomic? binary? hydrocarbon?) 3. Reverse the process used to name it so you can determine the formula. LecturePLUS Timberlake22

Tips for Identifying TYPE of Molecular Compound IF THE NAME HAS:TYPE OF COMPOUND HOW TO WRITE FORMULA Just the name of 1of Diatomic Element H 2, O 2, N 2, Cl 2, the following elements: Br 2, I 2, F 2 (HONClBrIF) Prefixes Binary (2 elements) Turn prefixes into Ends in “-ide” subscripts. (Write them after element symbol) Ends in “-ane” Hydrocarbon Look it up on list of hydrocarbons! LecturePLUS Timberlake23

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

LecturePLUS Timberlake26 Covalent Bonds in NH 3 (DON’T COPY) Bonding pairs H  H : N : H  Lone pair of electrons

Allotropes Def: molecules of the same element that differ in structure Ex 1: Carbon…graphite, charcoal, Buckminsterfullerine (“bucky ball”)= C 64 Ex 2: 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 ? (DON’T COPY) 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 element binary hydrocarbon (ends in –ane) acid/base 3. Reverse the naming process. LecturePLUS Timberlake29

STOP HERE!!! LecturePLUS Timberlake30

PLEASE NOTE: IF YOU ARE UNABLE TO IDENTIFY IONIC & COVALENT COMPOUNDS, YOU WILL BE LOST!!! PLEASE SEE ME IMMEDIATELY TO GET CAUGHT UP. LecturePLUS Timberlake31

Naming Binary Ionic Compounds 1. Name the cation, which is the given the name of the element. 2. Name the anion, which is given the name of the element, w/the ending changed to “–ide.” LecturePLUS Timberlake32

PRACTICE Naming Binary Ionic Compounds 1. Na║Cl 2. Na = “sodium” 3. Cl = “chloride” (full name is “sodium chloride”) LecturePLUS Timberlake33

PRACTICE Naming Binary Ionic Compounds 1. Li 2 O 2 & 3. ____║____= ______ ______ ( cation (anion (cation name) (anion name) symbol) symbol) LecturePLUS Timberlake34

LecturePLUS Timberlake35 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 Timberlake36 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 Timberlake37 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 Timberlake38 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