Unit 6 Name _______________________________ # ________ Section 1: Bonding 1. What is the duet rule and what elements follow it? What is the octet rule and what elements follow it? 2. How many valence electrons are in each of the following elements? a. b. c. d. e. C H Si Kr P _______ _______ _______ _______ _______ f. g. h. i. j. O N Cl Ar Cu _______ _______ _______ _______ _______ Answer the following questions. 3. What types of elements form ionic bonds? 4. What happens to the electrons in an ionic bond? 5. What types of elements form covalent bonds? 6. What happens to the electrons in a covalent bond? 7. Explain the difference between polar covalent and nonpolar covalent bonds. 8. Define electronegativity. 9. Express the periodic trend of electronegativity in words. 10. Record the electronegativities for the following elements. a. b. c. d. C H Si Kr _______ _______ _______ _______ e. f. g. h. O N Cl Ar _______ _______ _______ _______ 11. For each of the following pairs of elements, calculate the difference in their electronegativities. a. b. c. d. e. bond between 2 hydrogen atoms in H2 bonds between H and O in water bond between Na and Cl in sodium chloride bond between C and Cl in carbon tetrachloride bond between 2 chlorine atoms in Cl2 _______ _______ _______ _______ _______ 12. Using the letters to represent the six pairs above, order the bonds from those having the most polarity to those having the least. ___________________________________________________________ Section 2: Bond Types Determine if the bond in the following pairs of atoms is either ionic, polar covalent, or nonpolar covalent. If ionic show the charge (+ or -) and if polar covalent show the partial charge(δ+ , δ- ) on the appropriate atoms. 1. O–H bond type: __________________________ 2. N–N bond type: __________________________ 3. C–O bond type: __________________________ 4. K – Cl bond type: __________________________ 5. Mg – O bond type: __________________________ 6. As – O bond type: __________________________ 7. C–H bond type: __________________________ 8. N -- F bond type: __________________________ 9. P–H bond type: __________________________ 10. C – Cl bond type: __________________________ 11. P–O bond type: __________________________ 12. Si – I bond type: __________________________ 13. Fe – Cl bond type: __________________________ 14. Sr – S bond type: __________________________ Section 3: Binary Covalent Compounds Correctly name the following compounds. 1. IF5 _________________________________________________ 2. SeO _________________________________________________ 3. AsCl3 _________________________________________________ 4. B2O3 _________________________________________________ 5. P2O5 _________________________________________________ 6. SiBr4 _________________________________________________ 7. N2O5 _________________________________________________ 8. CO2 _________________________________________________ 9. B2H6 _________________________________________________ 10. H2O _________________________________________________ 11. Cl2S _________________________________________________ Correctly write the formula for the following compounds. 12. phosphorus triiodide ________________ 13. iodine monobromide ________________ 14. nitrogen trichloride ________________ 15. carbon monoxide ________________ 16. sulfur hexafluoride ________________ 17. dinitrogen tetroxide ________________ Section 4: Binary Covalent Compounds 1. Name the following compounds: a. N2O5 __________________________ b. SO3 __________________________ c. P4O10 __________________________ d. N2O __________________________ e. ClO2 __________________________ f. P2S5 __________________________ g. SO2 __________________________ h. CO2 __________________________ i. N2O4 __________________________ j. CO __________________________ 2. Write formulas for the following compounds: a. boron trichloride ____________________ b. phosphorus pentachloride ____________________ c. nitrogen dioxide ____________________ d. carbon tetrachloride ____________________ e. dichlorine heptoxide ____________________ f. dichlorine monoxide ____________________ g. nitrogen trichloride ____________________ h. triphosphorus hexafluoride ____________________ Section 5: Lewis Dot Diagrams I. Correctly draw the Lewis structure for the following elements in the spaces provided. a) Na b) Cl c) B d) Ne e) Mg f) Si g) P h) Se II. Correctly draw the Lewis structure for the following molecules in the spaces provided. a) H2 b) MgF2 c) BH3 d) CH4 e) H2Se f) AlCl3 g) KBr h) SrI2 i) NBr3 j) LiH k) Na2S l) GeI4 Section 6: Lewis Dot Diagrams Fill in the table below with the correct Lewis Dot Structure and the correct structural formula (replace bonded electrons with lines). CCl4 H2O CO2 O2 PH3 SF2 Br2 N2 NCl3 SiS2 Section 7: Lewis Dot Diagrams Correctly draw the Lewis Structure from each of the molecular formulas given in the spaces provided. 1. OH -1 2. CHN 3. SF6 4. SCN -1 5. XeF4 6. CS2 7. BrF3 8. Br3-1 9. BrO3-1 10. SbI5 11. NO3 -1 12. SO2 13. O -2 14. PO4 -3 15. CO3 -2 Section 8: VSEPR For each of the following molecules, draw the Lewis dot diagram, determine the electron group geometry, determine the molecular geometry, and draw the molecular structure, 3-D shape, of the molecule. 1. CF4 Electron group geometry _____________________ Molecular geometry _________________________ Lewis Structure: Molecular Structure: 2. NH3 Electron group geometry _____________________ Molecular geometry _________________________ Lewis Structure: Molecular Structure: 3. SO2 Electron group geometry _____________________ Molecular geometry _________________________ Lewis Structure: Molecular Structure: 4. CN-1 Electron group geometry _____________________ Molecular geometry _________________________ Lewis Structure: Molecular Structure: 5. BrCl5 Electron group geometry _____________________ Molecular geometry _________________________ Lewis Structure: Molecular Structure: 6. XeF4 Electron group geometry _____________________ Molecular geometry _________________________ Lewis Structure: Molecular Structure: 7. CH2O Electron group geometry _____________________ Molecular geometry _________________________ Lewis Structure: Molecular Structure: 8. IBr3 Electron group geometry _____________________ Molecular geometry _________________________ Lewis Structure: Molecular Structure: 9. IBr Electron group geometry _____________________ Molecular geometry _________________________ Lewis Structure: Molecular Structure: 10. PF5 Electron group geometry _____________________ Molecular geometry _________________________ Lewis Structure: Molecular Structure: Section 9: Molecular Models Lewis dot diagram Structural formula (dots only) (lines and dots) Geometry (Electron Group and Molecular) 1. CH4 EG: M: 2. O2 EG: M: Molecular Structure (3D) 3. H2 EG: M: 4. NH3 EG: M: 5. H2O EG: M: 6. SiCl4 EG: M: 7. CO2 EG: M: 8. PH3 EG: M: 9. C2H6 EG: M: 10. C2H4 EG: M: 11. C2H2 EG: M: Section 10: Intermolecular Forces 1. What is the difference between a non-polar and a polar molecule? 2. Which of the following compounds are polar? a. CO2 b. CH4 c. O2 d. H2O e. NH3 3. What are the 2 main types of IMF’s? 4. What is a dispersion force? 5. What two factors affect the amount of dispersion forces in a non-polar molecule? Describe the relationship between each factor and the amount of force. 6. How are the three types of dipole-dipole interactions different from each other? Section 11: Substance Types 1. Explain why network covalent compounds are very hard and non-polar covalent compounds are very soft. 2. You are given 4 compounds: diamond, methane (CH4), butane (C4H10), and magnesium chloride. Rank them in the order of increasing melting/boiling points. Justify your answer. 3. Why does surface tension increase with stronger IMF’s? What affect does this have on the boiling point of the substance? 4. What is viscosity? What is the relationship between viscosity and IMF’s?