Name Period CRHS Academic Chemistry UNIT 12 Chemical Bonding Practice Problems Due Date Assignment On-Time (100) Late (70) 12.1 12.2 12.3 12.4 12.5 Warm-Up EC Notes, Homework, Exam Reviews and Their KEYS located on CRHS Academic Chemistry Website: https://cincochem.pbworks.com
Unit 12 HW Page 2 of 12 WARM-UPS Day 1 Day 7 Day 2 Day 8 Day 3 Day 9 Day 4 Day 10 Day 5 Day 11 Day 6 Day 12
HW 12.1 INTRODUCTION TO CHEMICAL BONDING Unit 12 HW Page 3 of 12 1) How do atoms form bonds? 2) What electrons are involved in chemical bonding? 3) What is the Octet Rule? 4) What are the three types of chemical bonds? A. B. C. 5) Identify the following statements as either True or False Ionic bonds form between two metals Ionic bonds form between two nonmetals Ionic bonds form between metal and nonmetal Covalent bonds form between two metals Covalent Bonds form between two nonmetals Covalent bonds form between metal and nonmetal 6) Fill in the table using the electronegativity tables found on page 11. Atoms Li and Br Difference in Electronegativity Type of Bond H and S C and O K and F P and Cl S and I Mg and I Sn and F
HW 12.2 COVALENT, IONIC, AND METALLIC BONDING Unit 12 HW Page 4 of 12 Covalent Bonds 1) What is the Representative Particle for covalent compounds? 2) How is the Octet Rule achieved for atoms in a covalent bond? 3) Write the name or formula of the following covalent compounds: NO 2 Diphosphorous tetroxide Carbon tetrachloride Ionic Bonds 4) How is the Octet Rule achieved for atoms in an ionic bond? 5) What is an oxidation state? 6) What is the Representative Particle for ionic compounds? 7) What is a cation? 8) What is an anion? Metallic Bonds 9) Label the below statements as TRUE or FALSE. a. Metals (like steel) are made of ONLY periodic table metals, with no non-metals present. b. Valence electrons in a metal are stuck to the atom and do not move. c. The cations in a metal form a unique crystal pattern called a sphere 10) What gives metals the ability to be drawn into wire or hammered into shapes? 11) What holds the cations in a metal together? 12) List four unique properties of metals: a.
Unit 12 HW Page 5 of 12 b. c. d. e. 17) Give two examples of a metal alloy 18) Fill in the summary table Property Bond Type Representative particle Element makeup Physical State at room temp Melting/Boiling Point Soluble in water? Conductive? Examples Ionic Compounds/Bonds Electrons taken and given, ions form Crystalline solid YES BaBr2, LiClO3 Covalent Compounds/Bonds LOW Mildly H2O, CO2, C6H12O6 Metals Metallic Bonds of valence electrons move around cations Atom / crystal sphere Metals / metalloids Solid, liquid (mercury) Never Mg, Al, steel, bronze
12.3 LEWIS STRUCTURES FOR COVALENT MOLECULES Unit 12 HW Page 6 of 12 Covalent Molecules 1. How many total electrons do two atoms in a double bond share? 2. How many total electrons do two atoms in a triple bond share? 3. UNDERLINE the central atom in the following covalent compounds a. PF3 b. H2O c. CH4 d. HCN e. NH3 f. CO2 g. BBr3 h. SiCl4 4. Draw the Lewis structure of each of the following MOLECULES. F2 HCl # valence electrons Nitrogen triiodide Water HCN CH3I Silicon tetrachloride Silicon dioxide
12.4 LEWIS STRUCTURES FOR IONIC COMPOUNDS Unit 12 HW Page 7 of 12 1. Draw Lewis Structures for the following ELEMENTS Strontium Boron Silicon Bromine 2. Draw the Lewis Structures for the following CATIONS Calcium ion Potassium ion Barium ion Lithium ion 3. Draw the Lewis Structures for the following ANIONS Oxide ion Chloride ion Selenide ion Phosphide ion 4. Draw the Lewis Structures for these IONIC COMPOUNDS Lithium bromide Potassium oxide formula Barium chloride formula Calcium phosphide formula formula
Unit 12 HW Page 8 of 12 5. Draw Lewis structure of each of the following POLYATOMIC IONS NO3 ClO2 # valence electrons Phosphate ion Sulfite ion Carbonate ion NH4 +1
Unit 12 HW Page 9 of 12 12.5 MOLECULAR GEOMETRY 1. Define Molecular Geometry. 2. Write out the meaning of VSEPR 3. Complete the following table: Molecule Lewis Structure # of bonding groups on central atom # of lone pairs on central atom Molecular geometry Shape CF4 AsCl3 BH3 H2Se SiS2
Unit 12 HW Page 10 of 12 4. Determine if the following molecules are polar or nonpolar using the chart found in Unit 12 Notes on page 18. H 2 HF CCl 4 H 2 O NH 3 HI PCl 3 SO2
Unit 12 HW Page 11 of 12 20 Common Polyatomic Ions Name Ion Name Ion acetate C 2H 3O 2 or CH 3COO hypochlorite ClO ammonium +1 NH 4 nitrate NO 3 carbonate -2 CO 3 nitrite NO 2 chlorate ClO 3 perchlorate ClO 4 chlorite ClO 2 permanganate MnO 4 chromate -2 CrO 4 phosphate -3 PO 4 cyanide CN phosphite -3 PO 3 dichromate Cr 2O -2 7 silicate -2 SiO 3 hydrogen carbonate HCO 3 sulfate -2 SO 4 hydroxide OH sulfite -2 SO 3 H 2.1 Li 1.0 Na 0.9 Electro negativity (EN) Values Be 1.5 Mg 1.2 B 2.0 Al 1.5 C 2.5 Si 1.8 N 3.0 P 2.1 O 3.5 S 2.5 F 4.0 Cl 3.0 Difference in Type of Bond Electronegativity 0-0.3 Nonpolar-Covalent 0.3 1.7 Polar-Covalent >1.7 Ionic K 0.8 Ca 1.0 Ga 1.6 Ge 1.8 As 2.0 Se 2.4 Br 2.8 Rb 0.8 Sr 1.0 In 1.7 Sn 1.8 Sb 1.9 Te 2.1 I 2.5 Cs 0.7 Ba 0.9 Tl 1.8 Pb 1.9 Bi 1.9
Unit 12 HW Page 12 of 12