Test 8: Review Questions

Transcription

1 Name: Thursday, February 14, 2008 Test 8: Review Questions 1. Based on bond type, which compound has the highest melting point? 1. CH OH 3. CaCl C H 4. CCl Which compound contains ionic bonds? 1. NO 3. CaO 2. NO 2 4. CO 2 3. Which formula represents a nonpolar molecule? 1. H2S 3. CH4 2. HCl 4. NH 3 4. The balanced equation below represents a molecule of bromine separating into two bromine atoms. Br 2 Br + Br What occurs during this change? 1. Energy is absorbed and a bond is formed. 3. Energy is released and a bond is formed. 2. Energy is absorbed and a bond is broken. 4. Energy is released and a bond is broken.

2 5. Which compound contains only covalent bonds? 1. NaOH 3. Ca(OH) 2 2. Ba(OH) 4. CH OH What is the total number of electrons shared in a double covalent bond between two atoms? Which structural formula represents a linear nonpolar molecule containing two polar bonds? Which factor distinguishes a metallic bond from an ionic bond or a covalent bond? 1. the mobility of electrons 3. the equal sharing of electrons 2. the mobility of protons 4. the unequal sharing of electrons

3 9. Which Lewis electron-dot diagram is correct for CO? When metals combine with nonmetals, the metallic atoms tend to 1. lose electrons and become positive ions 3. gain electrons and become positive ions 2. lose electrons and become negative ions 4. gain electrons and become negative ions 11. A substance that has a melting point of 1074 K conducts electricity when dissolved in water, but does not conduct electricity in the solid phase. The substance is most likely 1. an ionic solid 3. a metallic solid 2. a network solid 4. a molecular solid 12. Which molecule contains a triple covalent bond? 1. H 2 3. O2 2. N 2 4. Cl2

4 13. Which elements combine by forming an ionic bond? 1. sodium and potassium 3. carbon and oxygen 2. sodium and oxygen 4. carbon and sulfur 14. A substance was found to be a soft, nonconducting solid at room temperature. The substance is most likely 1. a molecular solid 3. a metallic solid 2. a network solid 4. an ionic solid 15. Which type of bond is found in sodium bromide? 1. covalent 3. ionic 2. hydrogen 4. metallic 16. Which molecule contains a triple covalent bond between its atoms? 1. N 2 3. F2 2. O 2 4. H2 17. Metallic bonding occurs between atoms of 1. sulfur 3. fluorine 2. copper 4. carbon

5 18. In a nonpolar covalent bond, electrons are 1. located in a mobile "sea" shared by many ions 3. shared equally by two atoms 2. transferred from one atom to another 4. shared unequally by two atoms 19. Which structural formula represents a dipole? Figure 1 The table lists four different chemical bonds and the amount of energy released when 1 mole of each of the bonds is formed. Which bond is the most stable? 1. H-F 3. H-Br 2. H-Cl 4. H-I

6 21. What is the correct Lewis electron-dot structure for the compound magnesium fluoride? Which molecule contains a nonpolar covalent bond? Which of the following elements has the highest electronegativity? 1. H 3. Al 2. K 4. Ca

7 24. Figure 2 The table lists the melting points of various substances. Based on this table, which type of substance has the highest melting point? 1. nonpolar covalent 3. ionic 2. polar covalent 4. metallic 25. Which formula represents a nonpolar molecule? 1. CH 3. H O HCl 4. NH Which statement is true concerning the reaction N(g) + N(g) N 2(g) + energy? 1. A bond is broken and energy is absorbed. 3. A bond is formed and energy is absorbed. 2. A bond is broken and energy is released. 4. A bond is formed and energy is released. 27. Based on Reference Table S, the atoms of which of these elements have the strongest attraction for electrons in a chemical bond? 1. N 3. P 2. Na 4. Pt

8 28. Which formula represents a nonpolar molecule containing polar covalent bonds? 1. H O 3. NH CCl 4. H When an atom of chlorine forms an ionic bond with an atom of sodium, the atom of chlorine 1. loses an electron 3. becomes an ion with a smaller radius than the atom of chlorine 2. loses a proton 4. becomes an ion with a larger radius than the atom of chlorine 30. Which of the following solids has the highest melting point? 1. H2O(s) 3. SO 2(s) 2. Na2O(s) 4. CO 2(s) 31. An oxygen molecule contains a double bond because the two atoms of oxygen share a total of 1. 1 electron 3. 3 electrons 2. 2 electrons 4. 4 electrons 32. A white crystalline salt conducts electricity when it is melted and when it is dissolved in water. Which type of bond does this salt contain? 1. ionic 3. covalent 2. metallic 4. network

9 33. Which statement best describes the substance that results when electrons are transferred from a metal to a nonmetal? 1. It contains ionic bonds and has a low melting point. 3. It contains covalent bonds and has a low melting point. 2. It contains ionic bonds and has a high melting point. 4. It contains covalent bonds and has a high melting point. 34. Base your answer to the question on the information below. Given the balanced equation for dissolving NH Cl(s) in water: 4 Figure 3 - Which graphic below shows the correct orientation of each water molecule when it is near the Cl ion in the aqueous solution?

10 35. Base your answer to the question on the balanced equation below. 2Na(s) + Cl (g) 2 2NaCl(s) Which of the following choices shows the correct Lewis electron-dot diagram for a molecule of chlorine, Cl? Which formula represents an ionic compound? 1. NaCl 3. HCl 2. N2O 4. H2O 37. Which substance contains bonds that involved the transfer of electrons from one atom to another? 1. CO 2 3. KBr 2. NH 3 4. Cl Which substance is correctly paired with its type of bonding? 1. NaBr - nonpolar covalent 3. NH 3 - polar covalent 2. HCl - nonpolar covalent 4. Br 2 - polar covalent 39. If the electronegativity difference between the elements in compound NaX is 2.1, what is element X? 1. bromine 3. fluorine 2. chlorine 4. oxygen

11 40. As two chlorine atoms combine to form a molecule, energy is 1. absorbed 3. created 2. released 4. destroyed 41. Which type of bond is found in a molecule of methane? 1. a covalent bond 3. an ionic bond 2. a hydrogen bond 4. a metallic bond 42. Hydrogen bonding is strongest between molecules of 1. H2S 3. H2Se 2. H2O 4. H2Te 43. Hydrogen bonds are formed between molecules when hydrogen is covalently bonded to an element that has a 1. small atomic radius and low electronegativity 3. small atomic radius and high electronegativity 2. large atomic radius and low electronegativity 4. large atomic radius and high electronegativity 44. The van der Waals forces of attraction between molecules always become stronger as molecular size 1. increases, and the distance between the molecules 3. decreases, and the distance between the molecules increases increases 2. increases, and the distance between the molecules 4. decreases, and the distance between the molecules decreases decreases

12 45. What type of bonding is present within a network solid? 1. hydrogen 3. ionic 2. covalent 4. metallic 46. In which system do molecule-ion attractions exist? 1. NaCl(aq) 3. C H O (aq) NaCl(s) 4. C H O (s) Atoms of which element have the weakest attraction for electrons? 1. Na 3. Si 2. P 4. S 48. Which compound contains ionic bonds? 1. N2O 3. CO 2. Na2O 4. CO2 49. The kind of attractions that result in the dissolving of sodium chloride in water are 1. ion-ion 3. atom-atom 2. molecule-ion 4. molecule-atom

13 50. Which bond has the greatest ionic character? 1. H-Cl 3. H-O 2. H-F 4. H-N

14 Answer Key for Test 8: Review Questions

15 Test 8: Review Questions