ChemI/IH:Chapter8 Covalent Bonding (click for video)

1. ChemI/IH:Chapter8 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. LecturePLUS Timberlake

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

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

4. 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 Hydrochloric acid LecturePLUS Timberlake

5. 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: HClO3 ClO3 = “chlorate” chloric acid LecturePLUS Timberlake

6. 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: HClO2 ClO2 = “chlorite” chlorous acid LecturePLUS Timberlake

7. Acids, Summary(copy on P. Table) LecturePLUS Timberlake

8. 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 = H2hydrogen molecule LecturePLUS Timberlake

9. Covalent Bonding • single bond shares 1 pair electrons- ex:H2 • double bond shares 2 pairs electron-ex:O2 • triple bond shares 3 pairs electrons-ex: N2 LecturePLUS Timberlake

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 Timberlake

11. Solution(DON’T COPY) Indicate whether a bond between the following would be (I) Ionic OR (C) covalent I A. sodium and oxygen C B. nitrogen and oxygen C C. phosphorus and chlorine I D. calcium and sulfur C E. chlorine and bromine LecturePLUS Timberlake

12. 2. Diatomic Elements • Elements that exist as atom pairs • H2, O2, N2, Cl2, Br2, I2, F2, • They are given the name of the element. octets       N  + N  N:::N  triple bond LecturePLUS Timberlake

13. Learning Check(DON’T COPY) Use the name of the element to name a diatomic molecules. H2 hydrogen N2 nitrogen Cl2 _______________ O2 _______________ I2 _______________ LecturePLUS Timberlake

14. Solution(COPY) Use the name of the element to name the following diatomic molecules. H2 hydrogen N2 nitrogen Cl2chlorine O2oxygen I2iodine LecturePLUS Timberlake

15. 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 1st element listed) PREFIXES-COPY ONTO YOUR P. TABLE mono 1 hexa 6 di 2 hepta 7 tri 3 octa 8 tetra 4 nona 9 penta 5 deca 10 LecturePLUS Timberlake

16. Learning Check(DON’T COPY) Fill in the blanks to complete the following names of covalent compounds. CO carbon ______oxide CO2 carbon _______________ PCl3 phosphorus _______chloride CCl4 carbon ________chloride N2O _____nitrogen _____oxide LecturePLUS Timberlake

17. Solution(COPY!) CO carbon monoxide CO2 carbon dioxide PCl3 phosphorus trichloride CCl4 carbon tetrachloride N2O dinitrogen monoxide LecturePLUS Timberlake

18. Learning Check(DON’T COPY) A. P2O5 1) phosphorus oxide 2) phosphorus pentoxide 3) diphosphorus pentoxide B. Cl2O71) dichlorine heptoxide 2) dichlorine oxide 3) chlorine heptoxide C. Cl21) chlorine 2) dichlorine 3) dichloride LecturePLUS Timberlake

19. Solution(DON’T COPY) A. P2O5 3) diphosphorus pentoxide B. Cl2O71) dichlorine heptoxide C. Cl21) chlorine LecturePLUS Timberlake

20. 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.

21. Hydrocarbons • The table below lists only hydrocarbons w/single bonds • The names all end w/ “ane” (COPY ONTO YOUR P. TABLE) CH4 methane C6H14hexane C2H6 ethane C7H16heptane C3H8 propane C8H18octane C4H10 butane C9H20nonane C5H12pentane C10H22decane

22. 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 Timberlake

23. 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 • H2, O2, N2, Cl2, the following elements: Br2, I2, F2 (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 Timberlake

24. 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=

25. Frequently Used Common Names • Water = H2O • Ammonia = NH3

26. Covalent Bonds in NH3(DON’T COPY) Bonding pairs H   H: N : H   Lone pair of electrons LecturePLUS Timberlake

27. Allotropes • Def: molecules of the same element that differ in structure • Ex 1: Carbon…graphite, charcoal, Buckminsterfullerine (“bucky ball”)= C64 • Ex 2: O2 (oxygen) and O3 (ozone)

28. 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 • CO2

29. 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 Timberlake

30. STOP HERE!!! LecturePLUS Timberlake

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

32. 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 Timberlake

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

34. PRACTICE Naming Binary Ionic Compounds 1. Li2O 2 & 3. ____║____= ______ ______ (cation(anion (cation name) (anion name) symbol) symbol) LecturePLUS Timberlake

35. Learning Check Match each set with the correct name: A.Na2CO31) magnesium sulfite MgSO32) magnesium sulfate MgSO43) sodium carbonate B. Ca(HCO3)21) calcium carbonate CaCO32) calcium phosphate Ca3(PO4)2 3) calcium bicarbonate LecturePLUS Timberlake

36. Solution A.Na2CO33) sodium carbonate MgSO31) magnesium sulfite MgSO42) magnesium sulfate B. Ca(HCO3)23) calcium bicarbonate CaCO31) calcium carbonate Ca3(PO4)2 2) calcium phosphate LecturePLUS Timberlake

37. Learning Check A. aluminum nitrate 1) AlNO3 2) Al(NO)3 3) Al(NO3)3 B. copper(II) nitrate 1) CuNO3 2) Cu(NO3)2 3) Cu2(NO3) C. Iron (III) hydroxide 1) FeOH 2) Fe3OH 3) Fe(OH)3 D. Tin(IV) hydroxide 1) Sn(OH)4 2) Sn(OH)2 3) Sn4(OH) LecturePLUS Timberlake

38. Solution A. aluminum nitrate 3) Al(NO3)3 B. copper(II) nitrate 2) Cu(NO3)2 C. Iron (III) hydroxide 3) Fe(OH)3 D. Tin(IV) hydroxide 1) Sn(OH)4 LecturePLUS Timberlake