Chapter 6 Chemical Bonding

Transcription

1 Chapter 6 Chemical Bonding 1. Define electronegativity. 2. How does electronegativity vary as the atomic number of an element increases within the same period of the periodic table? 3. How is the strength of a bond between two elements in a molecule related to their electronegativities? 4. What is the difference between an ionic and a covalent bond? 5. How is the character of a bond (ionic or covalent) between two elements related to their electronegativities? 6. Referring to electronegativit.ies, in your text, arrange the following compounds in order of increasing ionic character of their bonds: LiBr, KCI, KI, LiF 7. Referring to Tables of electronegativities in your text, classify each of'the following bonds as either ionic: (I) or covalent (C) a. A1-O f. N-O b. Al-S g. Na-S c. Bi-CI h. P-O d. Bi-O i. S-O e. C- Cl j. Ti-Br 8. What force holds the two ions together in an ionic bond? 9. What is the meaning of the valence or charge of an element that forms an ionic bond? H. Cannon, C. Clapper and T. Guillot Klein High School

2 Chemical Bonding 10. Given the electron configurations for the following neutral atoms, predict the oxidation number each is most likely to have. Element Configuration Oxidation number A 1s 2 2s 2 2p 6 3s 2 B 1s 2 2s 2 2p 6 3s 1 C 1s 2 2s 2 2p 6 D 1s 2 2s 2 2p 5 E 1s 2 2s 2 2p Write the correct formula for each of the following combinations of elements from question 13. (If no reaction occurs, write none) a. B and D b. E and D c. A and D d. A and C 12. Underline the atom in each of the following pairs that has the lower electronegativity. a. Li Na b. Cs Rb c. Cs Ba d. Cl Br e. Fe Ni f. S Cl 13. List four general characteristics of compounds that have ionic bonds 14. Bonds between the which of the following pairs are Al Cl K F Ba Cl N O S O Fe O 15. List three general characteristics of compounds formed entirely by covalent compounds. 16. List three characteristics of metals. 17. How does the bonding of atoms in a metal differ from the bonding in a nonmetal? 6-2

3 Chemical Bonding Chapter 6 Bonding Worksheet 1) A chemical bond between atoms results from the attraction between electrons and what else? a. neutrons b. isotopes c. protons d. valence electrons 3) As the electronegativity difference between two atoms bonded together increases, the percentage of what else increases? a. ionic character b. covalent character c. metallic character d. electron sharing 5) What type of chemical bond results from the electrostatic attraction between positive and negative ions? a. ionic bond b. metallic bond c. polar covalent bond d. nonpolar covalent bond 2) What makes up a covalent bond? a. a shared electron b. two different ions c. an octet of electrons d. a shared electron pair 4) Which of the following would describe the electronegativity of an atom with a strong attraction for the electrons they share with another atom? a. high electronegativity b. low electronegativity c. zero electronegativity d. Lewis electronegativity 6) In a crystal of an ionic compound, each cation is surrounded by what? a. molecules b. positive ions c. dipoles d. negative ions 7. What do we call the electrons involved in forming a chemical bond? 8. If a bond s character is more than 50% ionic, what type of bond is formed? 9. If a bond s character is more than 50% ionic, what can we say about the electronegativity difference between the two atoms? 10. What is an example of an ionic compound? 11. Name two elements that form compounds that are exceptions to the octet rule. 12. How does the energy of the crystal lattice formed in an ionic compound compare with the energy of the neutral atoms involved in its formation? a. higher in potential energy b. lower in potential energy c. equal in potential energy d. unstable 13. What type of energy best represents the strength of an ionic bond? 14. What type of bonding holds a polyatomic ion together? 15. What type of forces holds two atoms together in an ionic bond? 6-3

4 Chemical Bonding Metallic Bonds 1) Which of the following best describes the valence electrons in metals? a. attached to particular positive ions b. shared by all surrounding ions c. immobile d. involved in covalent bonding 3) How does the strength of metallic bonds vary moving from left to right in any row of the periodic table? a. increases b. decreases c. remains the same 2) Which of these best explains why metals are malleable while ionic crystals are brittle? a. chemical bonds b. London dispersion forces c. heats of vaporization d. polarity 4) How does drawing a metal into a wire affect the metallic bonds? a. break easily b. break with difficulty c. do not break d. become ionic bonds 5. Use the concept of electron configuration to explain why the number of valence electrons in metals tends to be less than the number in most nonmetals. 6. How does the behavior of the electrons in metals contribute to the distinctive properties of metals? a. luster b. conductivity c. malleability d. ductility Complete the following table Metallic Ionic Components Overall charge Conductivity Melting point Hardness Malleability Ductility

5 Write the balanced ionic formulas: Cl -1 Na +1 Mg +2 Fe +3 Pb +4 NH 4 +1 O -2 P -3 OH -1 SO 4-2 PO 4-3 HSO 3-1 Cr 2 O

6 Draw dot diagrams for the following compounds: 1. Na + Cl 2. K + Br 3. Ba + F 4. Li + P 5. Mg + P 6. Ra + C! 7. Mg + S 8. Sr Cs + S 10. K + P 11. Ca Fr + F 13. Rb Ba + S 6-6

7 Binary Ionic Compounds Write the formula for the following: 1. Sodium bromide 18. Zinc phosphide 2. Calcium oxide 19. Chromium (III) oxide 3. Manganese(II) oxide 20. Antimony (V) sulfide 4. Silver (I) Chloride 21. Barium iodide 5. Nickel(III)Bromide 22. Potassium Sulfide 6. Ferric Oxide 23. Stannous oxide 7. Cupric nitride 24. Manganese (IV) fluoride 8. Silver (I) oxide 25. Zinc Sulfide 9. Aluminum nitride 26. Cobalt (II) iodide 10. Aluminum oxide 27. Plumbous Chloride 11. Magnesium sulfide 28. Mercury (I) oxide 12. Chromium (III) 29. Tin (IV) fluoride phosphide 13. Zinc iodide 30. Iron (III) Chloride 14. Ferrous fluoride 31. Tin (II) Sulfide 15. Lithium oxide 32. Copper (I) Bromide 16. Cuprous sulfide 33. Silver (I) iodide 17. Strontium nitride 6-7

8 Binary Ionic Compounds *Name using the Latin system 1. chromium (II) oxide 21. CaBr 2 2. strontium bromide 22. AlCl 3 3. copper (I) sulfide 23. PbO 2 * 4. mercuric iodide 24. Co 3 N 2 5. iron (II) sulfide 25. ZnO 6. ferrous fluoride 26. Mn 3 P 4 7. potassium bromide 27. MgI 2 8. cuprous oxide 28. AlP 9. iron (II) bromide 29. Fe 2 O 3 * 10. silver iodide 30. SnF 2 * 11. plumbous phosphide 31. BaS 12. barium sulfide 32. MnO Lead (II) fluoride 33. NaCl 14. copper (II) chloride 34. HgO* 15. lead (IV) sulfide 35. SnCl 4 * 16. mercury (II) bromide 36. NiBr lithium chloride 37. AlI tin (IV) nitride 38. CuF* 19. mercury (I) nitride 39. B 2 S stannous chloride 40. Na 2 O 6-8

9 Ionic compounds Name the following compounds 1. NH 4 NO AgC 2 H 3 O 2 2. Fe 2 (SO 3 ) NaI 3. BaCl FeSO 3 4. FeI Hg 2 Cl 2 5. CsS 25. Pb(C 2 H 3 O 2 ) 4 6. Sn(NO 3 ) NaOH 7. NaHCO KNO 3 8. KCl 28. SrSO 4 9. AlN 29. SrSO Ca 3 (PO 4 ) MgSO Li 2 O 31. (NH 4 ) 3 PO CrCl CuHCO Pb(NO 3 ) CoCO Cu 2 S 34. SnSO Ca(C 2 H 3 O 2 ) Na 2 CO Sb 2 S NH 4 CO Fe(C 2 H 3 O 2 ) NaI 18. Ba(OH) (NH 4 ) 2 SO Ag 2 SO Ca(C 2 H 3 O 2 ) MgO ZnBr 2 6-9

10 Naming Compounds Write the name for: 1. Fe(NO 2 ) KIO 2. (NH 4 ) 2 SO LiCN 3. Ag 2 SO CuCl 2 4. Zn(NO 3 ) CuBr 5. NH 4 Br 15. Fe(NO 3 ) 2 6. BaCO FeCl 3 7. Na 3 PO SnO 2 8. K 2 CrO HgCO 3 9. FeSO As(C 2 H 3 O 2 ) (NH 4 ) 3 PO NaClO 2 Write the formula for: 1. sodium chlorite 11. ammonium dichromate 2. iron (III) perbromate 12. lead (II) acetate 3. calcium chlorate 13. iron (III) oxide 4. calcium hypochlorite 14. cobalt (II) nitrate 5. copper (II) chlorate 15. strontium nitrite 6. cadmium iodate 16. tin (IV) oxide 7. chromium (III) sulfite 17. aluminum phosphate 8. bismuth (III) chromate 18. cobalt (II) hydroxide 9. barium nitrite 19. potassium permanganate 10. aluminum sulfate 20. Iron (II) sulfate 6-10

11 Write the name of the following compounds: 1. Ba(ClO 3 ) HMnO 4 2. Na 3 P 13. Mg(OH) 2 3. KOH 14. HBr 4. K 2 SO CaSO 4 5. Al 2( C 2 O 4 ) Ba(OH) 2 6. NH 4 OH 17. Al(OH) 3 7. Cu 3 (PO 3 ) HMnO 4 8. Li 2 CO H 2 CrO 4 9. Ag 3 PO Au(OH) K 2 SO4 21. NaCN 11. KF 22. K 2 SO

12 Naming Compounds Lab Purpose: To gain practice in writing formulas and naming compounds. Procedure: Using a spot plate as a reaction vessel, combine the first chemical and the second chemical. Be careful to use the bottle with the correct formula of the chemical named. Record any changes observed following the addition of the second chemical. Be careful not to touch the dropper to the spot plate well. If you do, it will cross-contaminate the reagent bottles. Each solution contains two ions, one positive and one negative. The product that we are interested in will be formed by combination of the underlined ions in the reactants Reactants Formula Pos. ion Copper (II) sulfate Sodium sulfide Copper (II) sulfate Ammonium hydroxide Aluminum iodide Ammonium hydroxide Potassium chromate Ammonium hydroxide Potassium chromate Silver (I) nitrate Potassium chromate Lead (II) nitrate Lead (II) nitrate Sodium phosphate Aluminum iodide Sodium phosphate Aluminum iodide Lead (II) nitrate Aluminum iodide Silver (I) nitrate Sodium phosphate Silver (I) nitrate Sodium sulfide Silver (I) nitrate Neg ion Ppt Color Formula Name 12