Name Chemistry 10 Dr. Kline 11 May 2004 Row Seat Lab 8:00 10:30

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1 Test 3 Name Chemistry 10 Dr. Kline 11 May 2004 Row Seat Lab 8:00 10:30 This test consists of a combination of multiple choice and other questions. There should be a total of 24 questions on 6 pages plus a page with equations and other information; please check to make sure that they are all here. You may use the equation/information sheet and any periodic table provided (last page). Do not use your own tables, scratch paper or other information. Do not share your calculator. Please turn off all cell phones, pagers and other communication devices; if they make noise, they will be confiscated. Shared calculators will be confiscated. It is OK to tear off the periodic table page. Multiple Choice Questions Each of the following 20 questions is worth three points, for a total of 60 points. There is only one correct answer for each question unless it is stated otherwise for a given question. Answer each question by circling the letter(s) corresponding to the correct choice(s); in other words, if there is more than one correct answer, circle all of the correct ones. It is not necessary to show work for these questions; however, you may write on the exam. 1. Which of the following elements has the largest ionization energy? a. fluorine b. bromine c. chlorine d. iodine 2. Which of the following elements has the smallest atomic radius? a. sulfur b. phosphorus c. magnesium d. chlorine e. silicon 3. Which of the following elements has the ground state electron configuration [Xe]6s 2 4f 14 5d 10 6p 3? a. Ba b. Bi c. Pb d. Te e. None of them 4. Which of the following has the same electron configuration as bromide ion, Br? More than one answer may be correct. a. Kr b. Se 2 c. Ca 2+ d. None of them 5. How many unpaired electrons are present in the ground state of nickel, Ni? a. 0 b. 1 c. 2 d. 3 e. 4 f. 5 g. more than 5 Chem 10 Test 3B page 1 of 5

2 6. The emission spectrum of lithium has lines at 460 nm, 547 nm, 617 nm, and 672 nm. Which of these corresponds to the electronic transition with the smallest energy difference? a. 460 nm b. 547 nm c. 617 nm d. 672 nm 7. Which of the following corresponds to the lowest pressure? a mm Hg b torr c. 1.4 atm d. 120 kpa 8. A mixture of gasses with a total pressure of 888 torr contains 2.0 mole Ne, 2.0 moles Kr, and 4.0 moles He. What is the partial pressure of Ne in the mixture? a. 111 torr b. 222 torr c. 444 torr d. 666 torr e. 888 torr 9. Which of the following gases has the greatest density at 25 C and 1.0 atm? a. CH 4 b. CH 3 F c. CH 3 Cl d. All of the densities are the same because the pressure and temperature is the same. e. It is impossible to tell. 10. A sample of gas is at a pressure of 777 torr in a 535-mL container at 65 C. Suppose that the temperature is changed to 45 C and the volume is increased to 835 ml. What of the following is true of the new pressure? a. P = 777 torr b. P > 777 torr c. P < 777 torr d. It is impossible to tell. 11. Which of the following gas samples, each containing 10.0 g of CH 4 in a 1.0-L container, has the highest pressure? a. The one in which the temperature is 25 C. b. The one in which the temperature is 75 C. c. The one in which the temperature is 45 C. d. They all have the same pressure. e. It is impossible to tell. 12. What is the molecular shape of PBr 3? a. Trigonal pyramidal b. Bent c. Octahedral d. Trigonal planar e. Linear f. Tetrahedral 13. Is the molecule CH 2 Cl 2 polar or non-polar? a. Polar b. Non-polar Chem 10 Test 3B page 2 of 5

3 Use the structures below to answer questions 14 and 15. O C N O C N O N C A B C 14. What is the relationship between structures A and C? a. Isomers b. Resonance structures 15. What is the relationship between structures A and B? a. Isomers b. Resonance structures 16. In the diatomic molecule F Cl are the electrons that comprise the single bond closer to fluorine or to chlorine? a. Fluorine b. Chlorine c. They are closer to neither since they are right in the middle. d. It is impossible to tell. 17. Consider the reaction 2A + 3B C + D. Suppose that 1.2 moles of A are used and the other reactant is in excess. How many moles of D could be produced? a b c. 1.2 d. 2.4 e What is the limiting reactant in the reaction 3A + 2B C + 4D when it is done using 1.5 moles of A and 1.2 moles of B? a. Reactant A b. Reactant B 19. What is the theoretical yield of KClO 3 in the reaction 2KCl + 3O 2 2KClO 3 if 0.25 moles of KCl are reacted with 0.50 moles of O 2? a moles b moles c moles d moles 20. Suppose that 5.6 g of Fe is combined with excess O 2 and the reaction 4Fe + 3O 2 2Fe 2 O 3 is allowed to go to completion, producing 7.0 g of Fe 2 O 3. What is the percent yield of Fe 2 O 3 for the reaction. The molar mass of Fe 2 O 3 is 160. a. 44% b. 38% c. 75% d. 93% e. 80.% f. 88% Chem 10 Test 3B page 3 of 5

4 Problems and Questions Each of the following is worth the indicated number of points, for a total of 40 points. Please show work, with units, to receive credit unless instructed otherwise. Also, be sure to provide all of the information requested for each question points Draw Lewis structures (lines for bonds; dots for lone pair electrons) for each of the following. It is only necessary to draw one resonance structure or isomer; make an attempt to draw the most reasonable one. a. + NO 2 b. SeBr 2 c. NI 3 d. C 2 H 2 Cl points Write a complete electron configuration using spdf notation and draw a complete orbital diagram (horizontal is OK) for copper, Cu, in its ground state. Configuration: Diagram: points Suppose that the reaction 2Al(s) + 2H 3 PO 4 (aq) 2AlPO 4 (aq) + 3H 2 (g) is done using 43.8 g of alumimum and excess phosphoric acid. e. What is the theoretical yield of hydrogen gas in grams? f. What volume of hydrogen gas would be collected at 1.15 atm and 37 C if the theoretical yield was obtained? points Calculate the molecular weight of a gas if 5.12 g of it occupies a volume of 1,430 ml at 45 C and 925 mm Hg. Could the gas be SO 2? Chem 10 Test 3B page 4 of 5

5 Chem 10 Information Sheet for Test 3 Spring 2004 Constants and Conversions h = 6.63 x J. s c = 3.00 x 10 8 m/s R = L. atm/mole. K = 62.4 L. mm Hg/mole. K K = C atm = 760 torr = 760 mmhg = kpa Electronegativity Values: C-2.5, N-3.0, O-3.5, Cl-3.0 Energy Equations DE = hu u = c l Gas Equations P1V1 = P2V 2 V1 T 1 = V 2 T 2 P1V1 T 1 P1V1 n1t 1 = P2V 2 T 2 = P2V 2 = R n2t 2 PT = PA + PB + Pc + L na PA = PT nt Chem 10 Test 3B page 5 of 5