4.2.A ReIntro to Bonding I Pledge : ( Initial ) DON T FORGET WHAT THIS REPRESENTS. Instructions: Provide a response for each question that is well thought out, satisfies the prompt, is clearly explained, and LEGIBLE. 1. Why do atoms and ions form bonds? s / s donate / accept / share e in order to form a low energy stable state (communally isoelectric to noble gases) _ 2. What is the difference between an intramolecular force and an intermolecular force (VERY IMPORTANT, differences must take into account EN and ity)? Intra- = Strong = Chemical = determined by EN resulting in and non molecules = between atoms / ions forming a molecule / FU (determines chemical. properties) _ Inter- = Weak = Physical = determined by ity and e movement = between molecules (determines physical properties ). 3. What role do e - play in ionic bonding and why? e are transferred from low EN atoms ( metals ) to a high EN atom ( nonmetals ) due to an EN 1.7. Difference. is enough that the more EN atom is able to rip away, or bully the high energy e of the low whimpy EN atom resulting in a permanent Coulombic attraction. 4. What role do e - play in covalent bonding and why? e are shared between high EN atoms ( nonmetals ) due to an EN < 1.7. Difference between the two high EN. bullies is not enough that one atom is able rip away the high e of the other so some form of imperfect sharing occurs. 5. What role do e - play in metallic bonding and why? e are shared between uniformly between low EN atoms ( metals ) due to an EN < 1.7. Difference between the two low EN wimps is not enough that ANY atom in the bond is able rip away the high e of the others so perfectly uniform sharing occurs = e sea. YOU NEED TO KNOW THESE!!!! Regarding Electronegativity Difference: It is somewhat artificial to classify bonds based on the differences in the electronegativities (ΔEN) of the two atoms. However, we will use these ranges to do so: ic ΔEN > 1.7 (symbolized as A + and Z ) Metallic ΔEN < 0.5 (symbolized as M1 δ+ and M2 δ+ ) Polar Covalent 1.7 ΔEN 0.5 (symbolized as A δ+ and Z δ ) Non-Polar Covalent ΔEN < 0.5 (symbolized as A 0 and Z 0 ) Instructions: Determine the electronegativity difference (ΔEN) for the following chemical bonds in the indicated blank. No work need be shown. Then using the ΔEN determine if the bond is considered a non covalent bond [NC], covalent [PC], ionic bond [I], or metallic bond [M]. Remember: EN = EN1 EN2, is NEVER a # ΔEN Bond Type ΔEN Bond Type ΔEN Bond Type 6. Li H 1.22 [PC]. 19. Cu Zn 0.25 [M]. 32. C H 0.35 [NC]. 0.98 2.20 EN 1.90 1.65 EN < 0.5 & 2M s 2.55 2.20 EN 7. Li Cl 2.18 [I]. 20. Ca Cl 2.16 [I]. 33. Si H 0.30 [NC]. 0.98 3.16 EN 1.7 1.00 3.16 EN 1.7 1.90 2.20 EN 8. Na H 1.27 [PC]. 21. Ca S 1.58 [PC]. 34. C O 0.89 [PC]. 0.93 2.20 EN 1.00 2.58 EN 2.55 3.44 EN 9. Na Cl 2.23 [I]. 22. Sr F 3.05 [I]. 35. Al Cl 0.96 [PC]. 0.93 3.16 EN 0.95 4.00 EN 1.7 2.20 3.16 EN 10. K H 1.38 [PC]. 23. Ba F 3.11 [I]. 36. C Cl 0.61 [PC]. 0.82 2.20 EN 0.89 4.00 EN 1.7 2.55 3.16 EN 11. K Cl 2.34 [I]. 24. Fr F 3.30 [I]. 37. H H 0.00 [NC]. 0.82 3.16 EN 1.7 0.70 4.00 EN 1.7 2.55 2.55 EN 12. Fr N 2.34 [I]. 25. H O 1.24 [PC]. 38. S O 0.86 [PC]. 0.70 3.04 EN 1.7 2.20 3.44 EN 2.58 3.44 EN 13. Fr Cl 2.46 [I]. 26. H S 0.38 [NC]. 39. P O 1.25 [PC]. 0.70 3.16 EN 1.7 2.20 2.58 EN 2.19 3.44 EN 14. Fe Fe 0.00 [M]. 27. H Se 0.35 [NC]. 40. Cs F 3.21 [I]. 1.83 1.83 EN < 0.5 & 2M s 2.20 2.55 EN 0.79 4.00 EN 1.7 15. Mg F 2.69 [I]. 28. H Br 0.76 [PC]. 41. O O 0.00 [NC]. 1.31 4.00 EN 1.7 2.20 2.96 EN 3.44 3.44 EN 16. Mg O 2.13 [I]. 29. H I 0.46 [NC]. 42. N O 0.40 [NC]. 1.31 3.44 EN 1.7 2.20 2.66 EN 3.04 3.44 EN 17. Cu Cu 0.00 [M]. 30. N H 0.84 [PC]. 43. Fe Co 0.05 [M]. 1.90 1.90 EN < 0.5 & 2M s 3.04 2.20 EN 1.83 1.88 EN < 0.5 & 2M s 18. Ca O 2.44 [I]. 31. P H 0.01 [NC]. 44. I Br 0.30 [NC]. 1.00 3.44 EN 1.7 2.19 2.20 EN 2.66 2.96 EN Remember: EN = EN 1 EN 2, is NEVER a #, PLEASE GO BACK AND ENSURE NO EN IS A #
4.2.B Lewis Structures, I Pledge : ( Initial ) DON T FORGET WHAT THIS REPRESENTS. Instructions: Draw Lewis Structures for each of the following atoms and then draw the Lewis Structures for its most common ion identifying how many valence electrons are present. Sodium Sodium # Val e- Calcium 1. Calcium 2. Aluminum Aluminum 3. Lead Lead (IV) 4. Nitrogen 5. Nitride # Val e- 8. Sulfur # Val e- 6. 8. Sulfide # Val e- Strontium Strontium 2. Selenium Selenide 6. Bromine 8. Bromide 7. 8. Instructions: For problems 19 30, given the following Lewis structures, provide the formula they represent. REMEMBER, the more EN atom is written last. Formula HF. Formula N2. Formula NH3. Formula CH4. Formula CF4. Formula NO +. Formula H4C3O3. Formula H6C2O. Formula H6C6. Formula PF5. Formula NH4 +. Formula ClO2. Instructions: For problems 31 46, for each formula given, write the correct Lewis electron-dot structure for the compound ON A SEPARATE SHEE OF PAPER. All 3 steps must be shown for CR. MUST SHOW ALL 3 Steps and circle final step to receive credit 31. CH4 33. PO3 3 32. C2H4 34. NO2
35. NF3 42. CN 36. Al H3 43. C2F2O2 37. H2O 44. SO2 2-38. C2H2 45. C6H12 (Hint: Ring) 39. O2 40. N2 46. C6H6 (Hint: Ring) 41. CH3COO Use hint of how the formula is written
4.2.C VSEPR, I Pledge : ( Initial ) DON T FORGET WHAT THIS REPRESENTS. Instructions: Provide a response for each question that is well thought out, satisfies the prompt, is clearly explained, and LEGIBLE. 1. What does VSEPR stand for and what it is it significance in determining chemical structures? Valence Shell Electron Pair Repulsion. The 3-D arrangement of a molecule is determined by the repulsion of it e pairs ( both bonding and non-bonding ). Note, lone pairs have a greater overall effect on. the structure due to being in a less defined space. Instructions: Given the following Lewis Structures, complete the table as indicated. Lewis Structure Chemical Formula Central Steric Number AXE Notation VSEPR Geometry Lewis Structure Chemical Formula Central Steric Number AXE Notation VSEPR Geometry BeCl2 Be 2 AX2 Linear C2H2 C 2 AX2 Linear BH3 B 3 AX3 Trigonal Planar C2H4 C 3 AX3 Trigonal Planar COH2 C 3 AX3 Trigonal Planar C2H4 C 3 AX3 Trigonal Planar CO2 C 2 AX2 Linear HF F 1 AXE3 Linear Instructions: For problems 10-24, identify what hybridization is required at the central atom of the following molecules or ions by sketching the Lewis electron-dot diagram; state the Steric Number (SN), then state the AXE notation, the molecular geometry, and whether the molecule is or non. 10. AlCl3 11. BCl3 12. SCl2 4 2 Bonded + 2 Lone Pairs AX2E2 13. NO2 + 2 2 Bonded + 0 Lone Pairs AX2 14. ClO4-4 4 Bonded + 0 Lone Pairs AX4 non non bent a is an ion tetrahedral is an ion 15. PCl3 4 3 Bonded + 1 Lone Pairs AX3E 16. BF3 17. CCl4 4 4 Bonded + 0 Lone Pairs AX4 18. GaH3 19. BeCl2 2 2 Bonded + 0 Lone Pairs AX2 trigonal pyramidal a non tetrahedral non non a
20. PCl5 5 5 Bonded + 0 Lone Pairs AX5 21. SiCl4 4 4 Bonded + 0 Lone Pairs AX4 22. NCl3 4 3 Bonded + 1 Lone Pairs AX3E 23. OCS 2 2 Bonded + 0 Lone Pairs AX2 24. ClF2 + 4 2 Bonded + 2 Lone Pairs AX2E2 Trigonal bipyramidal non tetrahedral non trigonal pyramidal a asymmetric charge distribution due to differences in O / S. is an ion 4.2.D Compounds: Polarity and Lattices I Pledge : ( Initial ) DON T FORGET WHAT THIS REPRESENTS. Instructions: For each of the bonds listed below, classify each bond as either non covalent bond [NC], covalent [PC], ionic bond [I], or metallic bond [M] based on ΔEN and indicate full ( + / ), partial charges ( δ+ / δ ), or no charge ( 0 ). + δ+ δ δ+ δ + 1. I Na Cl 3. PC Mg H 5. PC C O 7. I Cs F 0.93 3.16 1.31 2.20 2.55 3.44 0.79 4.00 δ+ δ 0 0 0 0 δ+ δ 2. PC Cu O 4. NC Cl Cl 6. NC C H 8. PC Al C 1.90 3.44 3.16 3.16 2.55 2.20 2.20 2.55 Instructions: For each of the bonds listed below, indicate the direction of bond ity ( ), or if no ity ( ) 9. Na Cl 11. Mg H 13. C O 15. Cs F 0.93 3.16 1.31 2.20 2.55 3.44 0.79 4.00 10. Cu O 12. Cl Cl 14. C H 16. Al Cl 1.90 3.44 3.16 3.16 2.55 2.20 2.20 2.55 Instructions: For problems 17 30, indicate the strongest IMF (not a trick question) holding together crystals of the following: Dispersion Forces Molecular Crystals Metal ic Crystals Dipole- Dipole Hydrogen Metallic ic Network Solid Covalent 17. NH3 X 32. N2 X No metals involved, bond is and is N w/ H. Remember that H w/ N, O or F is hydrogen bonding Molecular Crystals Metal ic Crystals Dispersion Forces Dipole- Dipole Hydrogen Metallic ic No metals involved, no bond. As this is an element bonded to itself, no permanent IMF s exist Network Solid Covalent 18. Kr X 33. CH3OH X No metals involved, no bond. Also this is a noble gas, so no permanent IMF s exist No metals involved, is A bond and is O w/ H. Remember that H w/ N, O or F is hydrogen bonding 19. HCl X 34. Ag X No metals involved, bond is but is not H w/ N, O or F 20. F2 X 35. NaOH X No metals involved, no bond. As this is an element bonded to itself, no permanent IMF s exist Metal involved with a ionic bond present. 21. KMnO4 X 36. Al X Metal involved with a ionic bond present. 22. NaCl X 37. PCl3 X Metal involved with a ionic bond present. No metals involved, bond is but is not H w/ N, O or F. Also asymmetrical charge distribution 23. SO2 X 38. XeF4 X No metals involved, bond exists between S O. Also has a bent shape No metals involved, bond is but charge distribution is symmetrical. 24. CO2 X 39. He X No metals involved, no bond. Symmetrical charge distribution with its shape. No metals involved, no bond. Also this is a noble gas, so no permanent IMF s exist 25. C6H6 X 40. Na X No metals involved, no bond. 26. NO X 41. CO X
No metals involved, bond exists between N O. Also an asymmetrical charge distribution No metals involved, bond exists between C O. Also an asymmetrical charge distribution 27. H2SO4 X 42. Ar X No metals involved, bond is but is not H w/ N, O or F No metals involved, no bond. Also this is a noble gas, so no permanent IMF s exist 28. WC X 43. Ba(OH)2 X Metal involved with a ionic bond present. The hint that this isn t just dipole-dipole is lack of subscripts. Metal involved with a ionic bond present. 29. Si X 44. O2 X One of three covalent networks that we are supposed to recognize. No metals involved, no bond. As this is an element bonded to itself, no permanent IMF s exist 30. SiO2 X 45. Hg X AKA quartz, one of three covalent networks that we are supposed to recognize. 31. C(graphite( X 46. XeF2 X One of three covalent networks that we are supposed to recognize. No metals involved, bond is but charge distribution is asymmetrical unlike #22.