DATE Chapters 7 & 8 TEST REVIEW

Transcription

1 NAME PERIOD DATE Chapters 7 & 8 TEST REVIEW Remember you may use one 3x5 card (ONE SIDE ONLY WITH NO POLYATOMIC IONS) for notes on the test. On the test there will be review questions from previous tests and quizzes. The following 10 questions are TRUE or FALSE. Write TRUE or FALSE on the blank next to each question. 1. Elements in the same family tend to have the same number of valence electrons. 2. When an atom gains electrons its radius gets smaller. 3. The number of valence electrons an element has is the most important characteristic in determining its chemical properties. 4. The change of an atom from an excited state to the ground state always requires the emission of electromagnetic radiation. 5. Ionic compounds have high MPs, high BPs, but are poor electrical conductors. 6. Metallic bonds are flexible making metallic compounds malleable and ductile. 7. Ionic compounds are soluble in water. 8. Forming a covalent compound is endothermic. 9. Water is a nonpolar molecule. 10. Chemists once theorized that a molecule that contains a single bond and a double bond splits its time existing as one of these two structures. This effect became known as multiple bonding. The following 20 questions are MULTIPLE CHOICE. Write A, B, C, or D on the blank next to each question. 11. Which scientist used his arrangement of the periodic table to predict the properties of missing elements, which were identified a few years later? a. Mendeleev c. Newlands b. Lavoisier d. Moseley 12. Which of these elements has 5 valence electrons? a. Boron (B) c. Vanadium (V) b. Rubidium (Rb) d. Arsenic (As) 13. In which pair is the one on the left larger than the one on the right? a. Na, Rb c. Br, Br - b. S, Mg d. K, K What is the number of neutrons in 35Br? a. 35 c. 80 b. 45 d Metallic elements tend to when forming ions. a. Gain electrons b. Lose electrons c. Share electrons d. Neither a, b, or c

2 16. Which of the following is not a popular electrolyte found in the human body? a. Ca 2+ c. Na + b. K + d. Co The bond energies of F2, O2, and N2 are 159 kj/mol, 498 kj/mol, and 945 kj/mol respectively. Which of the following compounds has the shortest bond? a. F2 d. Can t tell from the information b. O2 given. c. N2 18. Which of the following bonds has the greatest ionic character? a. Si O c. Na O b. Fe O d. C O 19. Which of the following compounds is nonpolar? a. H2S c. NH3 b. CCl4 d. H2O 20. Which of the following separation techniques is based on boiling points? a. Chromatography c. Distillation b. Sublimation d. Filtration 21. Which of the following is described as a transfer of electrons? a. Covalent bond c. Hydrogen bond b. Metallic bond d. Ionic bond 22. How many total valence electrons does the Lewis dot structure for the ammonium ion have? a. 9 c. 20 b. 8 d Which of the following intermolecular forces is the strongest? a. Ionic bond c. Dipole-dipole force b. Hydrogen bond d. Dispersion (London) force 24. Which of the following best describes a dispersion (London) force? a. Temporary dipoles attract c. Hydrogen and oxygen attract b. Permanent dipoles attract d. None of the above 25. Which of the following elements is never included in a hydrogen bond? a. Hydrogen c. Chlorine b. Oxygen d. Nitrogen 26. Which of the following compounds would have the highest MP (melting point)? a. H2S c. H2Se b. H2O d. H2Te 27. Which of the following compounds would have the lowest BP (boiling point)? a. CH3OH c. HCl b. CH4 d. C10H Which of the following exhibits dipole-dipole attractions between molecules? a. Cl2 b. CO2 c. NH3 d. H2

3 29. A chemical bond formed by the attraction between metal cations and delocalized electrons is a(n) a. Nonpolar covalent bond c. Polar covalent bond b. Ionic bond d. Metallic bond 30. The greater the electronegativity difference between 2 bonded atoms, the greater the percentage of in the bond. a. Ionic character b. Covalent character c. Metallic character d. Election sharing The following 10 questions are SHORT ANSWER. Answer them as completely as possible. Don t forget to show your work and also to include units. 31. Write the complete electron configuration for the Selenium ion. 32. What is the mass of 5.6 moles of CaCl2? 33. Explain why molecular compounds have low MPs and low BPs. 34. Explain how metals form ions and how nonmetals form ions. 35. Explain why calcium can form a Ca 2+ ion but not a Ca 3+ ion.

4 36. Complete the following table on naming compounds and writing formulas: NAME FORMULA TYPE (acid, ionic, or molecular) Hydrobromic acid Lead (IV) chlorite Strontium phosphide Ammonium phosphite Chlorous acid Gallium hydroxide Potassium permanganate Copper (II) phosphate Manganese (III) dichromate Pentanitrogen trioxide HCl HNO2 Se3F8 P3I6 FeSO3 Na2C2O4 ICl Pb(ClO3)3 H2S SO3

5 37. Using the table below, identify which compound is the strongest and explain how you can tell. Lattice Energies of Some Ionic Compounds Compound Lattice Energy (kj/mol) Compound Lattice Energy (kj/mol) KI 632 AgCl 910 KBr 671 NaF 910 RbF 774 LiF 1030 NaCl 769 SrCl KF 808 MgO Explain how an ionic compound forms between sodium and nitrogen. 39. Draw the Lewis dot structure for hydrocyanic acid and label the sigma and pi bonds. 40. Fill in the following table using the VSEPR model. Compound Ammonia Lewis Dot Structure Molecular Shape Bond Angle Polarity (polar or nonpolar) Hybrid Orbital Methane Water