Name period Unit 3 worksheet

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1 Name period Unit 3 worksheet Read chapter 8, Explain the difference between metallic, ionic, and covalent bonding Metallic cations share a sea of electrons Ionic atoms give and take electrons Covalent atoms share electrons 2. Why can metals conduct electricity? electrons are free to move around 3. Predict the chemical formula of the ionic formed between the following pairs of elements a. Al and F b. K and S c. Mg and N d. Ba and O AlF 3 K 2 S Mg 3 N 2 BaO 4. Define the term lattice energy and tell what factors govern the magnitude of the lattice energy of an ionic. The amount of energy that is required to break an ionic bond. The magnitude depends on the charge of the ion and the size of the ion. smaller ions and more charge have higher lattice energy. 5. Arrange the following substances according to their expected lattice energies, listed them from lowest lattice energy to highest: LiCl, KCl, KBr, CaO KBr< KCl < LiCl < CaO 6. a. The lattice energies of NaF and MgO are given in table 8.2. Account for the difference in these two quantities. MgO has higher charges so the lattice energy is higher b. Account for the difference in the lattice energies of MgCl 2 and SrCl 2, which are also listed in the table. Mg is smaller than Sr, so the lattice is greater 7. Explain the following trends in lattice energy a. MgO > MgS b. LiF > CsBr c. CaO > KF Oxygen is smaller than S Cs is larger than Li CaO has larger charges than KF Br is larger than F 8. How is bonding in Cl 2 different than NaCl? In Cl 2, the electrons are being shared between the two chlorine atoms, but in NaCl, the Cl is taking the electron from the sodium 9. Explain why a Br atom in Br 2 satisfies the octet rule whereas a free Br atom does not. Br has 7 valence electrons, but when it bonds to itself they both contribute an electron to share so they each feel 8 electrons around them. 10. Draw the Lewis structure for O 2. The bond in O 2 is shorter than the OO single bond. Explain this observation. O=O A double bond is shorter than a single bond 11. Predict whether the following s are molecular or ionic a. B 2 H 6 b. CH 3 OH c. LiNO 3 d. Sc 2 O 3 e. CsBr f. NOCl g. Ag 2 SO 4 Molecular molecular ionic ionic ionic covalelnt ionic

2 12. Which of the following bonds are polar? a. PO b. SF c. BrBr 13. Arrange the bonds in order of increasing polarity a. CF, OF, BeF b. NBr, PBr, OBr OF, CF, BeF PBr, NBr, OBr 14. Label each as ionic, polar covalent, or nonpolar covalent a. CO b. MgO c. Cl 2 d. AlF 3 Polar covalent ionic nonpolar covalent ionic 15. Draw the Lewis structure for the following see in class a. CO b. N 2 c. SF 2 d. ClO 2 e. PCl 3 e. H 2 CO (both H bonded to C) 16. A.Draw the Lewis electrondot structures for CO 3 2, CO 2 and CO, including resonance structures where appropriate. See in class b. Which of the three species has the shortest CO bond length? Explain the reason for your answer. CO carbon monoxide forms triple bonds which are shorter than double in CO 2 and the 1 1/3 bond in CO 3 c. Account for the fact that the carbonoxygen bond length in CO 3 2 is greater than the carbonoxygen bond length in CO /3 bond is longer than a double bond 17. How can the concept of resonance be used to explain that all six CC bonds in benzene are equal in length. The 3 double bonds are being shared between all 6 atoms so the bond order for each CC bond is Use simple structure and bonding models to account for each of the following: (a) The bond length between the two carbon atoms is shorter in C 2 H 4 than in C 2 H 6. C 2 H 4 forms double bonds and C2H6 forms single bonds. Double bonds are shorter than single (b) All the bond lengths in SO 3 are identical and are shorter than a sulfuroxygen single bond. SO 3 forms resonance so the bonds are each 1 1/3 which is shorter than a single 19. Draw the Lewis structure for each of the following molecules see in class 2 a. CO 3 b. BH 3 c. I 3 d. XeF 4 e. AsF In the Lewis structure for CH 2 Cl 2, the number of unshared electron pairs a. 2 b. 8 c. 10 d. 6 e In which of the following s does the bond between the central atom and chlorine have the greatest ionic character? a. BCl 3 b. HCl c. FeCl 2 d. CCl 4 e. CaCl Nitrogen is the central atom in each of the species given above. Draw the Lewis electrondot structure for each of the three species. See in class 23. Which one of the following molecules contains a triple bond? a. PF 3 b. NF 3 c. C 2 H 2 d. H 2 CO e. HOF

3 24. Which of the following has the greatest dipole moment? a. H 2 b. HCl c. HF d. CO 25. Which of the following will conduct electricity? (there can be more than one answer) a. solid Mg b. solid NaCl c. aqueous MgCl 2 d. liquid Sn e. solid CO 2 f. liquid N Predict which of the following will have the highest boiling point a. CO 2 b. N 2 c. NaCl 27. Which of the following ionic s has the smallest lattice energy? a. Na 2 O b. LiF c. CaO d. CaCl 2 e. MgS 28. What are structural isomers? Draw two isomers of pentane. See in class 29. give the formula for each of the following a. pentane C 5 H 12 c. 2Hexene C 6 H 12 e. 1butyne C 4 H 6 g. benzene C 6 H 6 b. heptane C 7 H 16 d. proponol C 3 H 7 OH f. ethane C 2 H 6 h. methane CH Calcium reacts with element X to form an ionic. If the groundstate electron configuration of X is 1s 2 2s 2 2p 4, what is the simplest formula for this? a. CaX b. CaX 2 c. Ca 4 X 2 d. Ca 2 X 2 Nonmetal C N O Ne Si P S Ar Formula of CF 4 NF 3 OF 2 No SiF 4 PF 3 SF 2 No 31. Some binary s that form between fluorine and various nonmetals are listed in the table above. A student examines the data in the table and poses the following hypothesis: the number of F atoms that will bond to a nonmetal is always equal to 8 minus the number of valence electrons in the nonmetal atom. (a) Based on the student s hypothesis, what should be the formula of the that forms between chlorine and fluorine? ClF (1 point is earned for correct formula) (b) In an attempt to verify the hypothesis, the student researches the fluoride s of the other halogens and finds the formula ClF 3. Draw a complete Lewis electrondot diagram for a molecule of ClF 3. see in class (1 point is earned for a central Cl atom surrounded by three bonding pairs with F atoms and two nonbonding (lone) pairs of electrons. F atoms must have three nonbonding pairs each. Electron pairs can be depicted as dots or line segments In an attempt to resolve the existence of the ClF 3 molecule with the hypothesis stated above, the student researches the s that form between halogens and fluorine, and assembles the following list Halogen Formula(s) F F 2 Cl Br BrF, BrF 3, BrF 5 I IF, IF 3, IF 5, IF 7 (c). Based on concepts of atomic structure and periodicity, propose a modification to the student s previous hypothesis to account for the s that form between halogens and fluorine. An acceptable hypothesis must include the following ideas: 1. Atomic structure: e.g., odd number of F atoms

4 2. Periodicity: e.g., as the atomic number of the central halogen atom increases, the number of F atoms increases (1 point is earned for an acceptably modified hypothesis that addresses both atomic structure and periodicity) 32. Bronze (Cu and Sn); Steel (Fe and C). Which of the following correctly describes the malleability of both alloys compared to their primary metal? b. Bronze s malleability would be comparable to that of copper, but steel s malleability would be significantly lower than that of iron. c. Bronze s malleability would be significantly higher than that of copper, but steel s malleability would be comparable to that of iron. d. Both bronze and steel would have malleability values similar to those of their primary metals e. Both bronze and steel would have malleability values greater than those of their primary metal. Review 33. Calcium reacts with element X to form an ionic. If the groundstate electron configuration of X is 1s 2 2s 2 2p 4, what is the simplest formula for this? a. CaX b. CaX 2 c. Ca 4 X 2 d. Ca 2 X A. What are valence electrons? Electrons in the highest energy level a. How many valence electrons does nitrogen have? 5 c. An atom has the electron configuration 1s 2 2s 2 2p 6 3s 2 3p 2. How many valence electrons does this atom have? If an atom has the electron configuration 1s 2 2s 2 2p 5, how many electrons must it gain to achieve an octet? Fill in the gaps Symbol 52 Cr I 107 Ag Sn As 3 Protons Neutrons Electrons Net charge What is the nuclear charge for the following atoms a. Na b. F c. Sn d. P e. Ar Why doesn t a valence electron feel the full nuclear charge of an atom? The nucleus is shielded by other electrons 39. Which atom will have the largest radius in each pair. a. K, Na b. Na, Na+ c. Br, Br d. K, Br 40. Which property generally increases down a group but decreases from left to right b. Melting point b. electronegativity c. ionization energy d. atomic radius 41. A.What is the name of group 1? Alkali metals b. What is the name of group 17? halogens

5 42. Which pair of elements has the most similar properties? c. Na, S b. N, P c. P, Cl d. N, Cl 43. Convert d g of magnesium chloride to moles mol e. 5.3 x molecules of nitrogen dioxide to grams 41 g f moles of ammonia to milligrams mg 44. Write the electron configuration for each of the following ions c. Sr 2+ b. Ni 2+ c. Br d. Mn 3+ [Kr] [Ar]3d 8 [Ar]4s 2 3d 10 4p 6 [Ar]3d Write a balanced net ionic reaction a. manganese (II) nitrate solution is mixed with sodium hydroxide solution. Mn OH Mn(OH) 2 b. hydrosulfuric acid is added to a solution of barium hydroxide and a precipitate forms. 2H 2 S + Ba OH BaS + 2H 2 O c. fluorine is added to a magnesium chloride solution. Halogens are soluble except with silver, mercury, and lead F 2 + 2Cl Cl 2 +2 F d. potassium is added to water K + H 2 O K + + OH + H Which is a list of elements listed in order of increasing ionization energy? A) Na, K, Rb B) Ne, Ar, Kr C) Al, Mg, Na D) Br, Cl, F E) O, S, Se Name or give the formula for each of the following 46. silver sulfide Ag 2 S 64. MnO manganese (II) oxide 47. sodium sulfite Na 2 SO P 5 O 4 pentaphosphorus tetroxide 48. magnesium sulfate MgSO Fe(OH) 2 iron(ii) hydroxide 49. iron (III) sulfide Fe 2 S NiCr 2 O 7 nickel(ii) dichromate 50. zinc phosphate Zn 3 (PO 4 ) Cu 2 S copper (I) sulfide 51. hydrosulfuric acid H 2 S 69. HCl hydrochloric acid 52. barium acetate Ba(C 2 H 3 O 2 ) CO carbon monoxide 53. copper (I) permanganate CuMnO H 2 SO 3 sulfurous acid 54. carbonic acid H 2 CO Cs 2 CO 3 cesium carbonate 55. strontium cyanide Sr(CN) NH 4 ClO 4 ammonium perchlorate 56. dinitrogen trioxide N 2 O Ba(CH 3 COO) 2 barium acetate 57. silver nitride Ag 3 N 75. FePO 4 iron (III) phosphate 58. hydrobromic acid HBr 76. CaF 2 calcium fluoride 59. calcium hydroxide Ca(OH) H 3 PO 4 phosphoric acid 60. nitric acid HNO MgBr 2 magnesium bromide 61. acetic acid HC 2 H 3 O NaHCO 3 sodium bicarbonate 62. ammonia NH H 2 O 2 hydrogen peroxide