ACSBR 2E Chemical Bonding (Extensions) - Assignment ANS

Anglo-Chinese School (Barker Road) A Methodist Institution Founded in 1886 CHEMISTRY DEPARTMENT OF SCIENCE Name: ANSWERS ( ) Class: SEC 3 CHEMICAL BONDING (EXTENSIONS) – ASSIGNMENT ALEX LEE/2010 PAGE 1 OF 5 PURE Multiple-Choice Questions [20 Marks] TOTAL SCORE / 30 Write in your selected answer for the multiple-choice questions in the boxes provided. 1 2 3 4 5 6 7 8 9 10 D C C B A C B A B A 11 12 13 14 15 16 17 18 19 20 C B B D B D D B C B 1. How many chloride ions are adjacent to each sodium ion in a crystal of sodium chloride? A 1 B 2 C 4 D 6 2. An element Q reacts with chlorine to form a liquid of formula QCl2. What could be the electronic configuration of Q? A 2, 8, 1 B 2, 8, 2 C 2, 8, 6 D 2, 8, 8 3. A ‘dot and cross’ diagram showing the bonding in ammonium chloride (NH4Cl) is shown. From the above diagram, we can tell that ammonium chloride contains A covalent bonds only. C both covalent and ionic bonds. B ionic bonds only. D neither covalent nor ionic bonds. 4. In a molecule of methane (CH4), how many pairs of electrons are not involved in bonding? A 0 B 1 C 2 D 4 5. Which one of the following solids does not contain covalent bonds? A copper B diamond C methane D ice

ALEX LEE/2010 PAGE 2 OF 5 6. Which one of the following solids does not contain intermolecular forces? A graphite B iodine C sand D sulfur 7. Which of the following substances would best be used as a refractory material, i.e. able with withstand very high temperatures? A a metal C a non-metallic oxide B a metallic oxide D a plastic 8. Which of the following is not a property of pure calcium? A It has a hard, strong texture. C It is shiny in appearance. B It is able to conduct electricity. D It is solid at room temperature. 9. Which of the following elements would we expect to have the highest melting point? A argon B carbon C chlorine D mercury 10. Graphite can be used for all of the following except A as a drill bit and in heavy-duty cutting. C as a lead in pencils. B as a dry lubricant in industrial applications. D as an electrode to conduct electricity. 11. In the structure of graphite, sheets of carbon atoms are able to slide over each other easily A due to the presence of delocalized electrons between the sheets of carbon atoms. B due to the regular hexagonal arrangement of each sheet of carbon atoms. C due to the weak intermolecular forces between the sheets of carbon atoms. D due to the weak single covalent bond between the carbon atoms. 12. The structure of diamond can best be described as A a macromolecular structure with a hexagonal arrangement of carbon atoms. B a macromolecular structure with a tetrahedral arrangement of carbon atoms. C a simple molecular structure with a octahedral arrangement of carbon atoms. D a simple molecular structure with a trigonal arran