Chemistry Section 1 Different Types of Solids

CНEMISТRY SECТIONI Note: For all questions, assume that the temperature is 298 К, the pressure is 1.00 atmosphere, and s olutions are aqueous unless otherwise specified. Throughout the test the following symbols have the definitions specified unless otherwise noted. Т = temperature Р = pressure V= volume S = entropy Н= enthalpy G = free energy R = molar gas constant п = number of moles М = molar т = molal L, mL = liter(s), miШliter(s) g = gram(s) nm = nanometer(s) atm = atmosphere(s) J, kJ = joule(s), kilojoule(s) = volt(s) V mol = mole(s) PartA Direc6ons: Each set of lettered choices below refers io the numЬered statements immediately following it. Select the one !ettered choice that best fits each statement and then fШ in the corresponding oval on the answer sheet. А choice may Ье used once, more than once, or not at all in each set. Ouestions 1-4 refer to the following types of energy. (А) Activation energy (В) Free energy (С) Ionization energy (D) Кinetic energy (Е) Lattice energy 1. The energy required to convert а ground-state atom the gas phase to а gaseous positive 2. The energy change that occurs in the conversion of а.'1 ionic solid to widely separated gaseous ions 3. The energy in а chemical or physical change that is availaЫe to do useful work 4. The energy required to form the transition state in а cheniical reaction Questions 5-8 refer to atoms for wblch the occupied atomic orbltals are shown below. (А) 1s __2s_t_ (В) ls___tL2s_lL (С) ls___tL2s_lL2p_i_ __i___ {D) ls___tL2s_lL2p___tL_lL_lL (Е) [Ar] 4s____tl_Зd_lL_t____ t __ t i_ 5. Represents an atom that is chemically unreactive 6. Represents an atom in an excited state 7. Represents an atom that has four valence electrons 8. Represents an atom of а transition metal Ouestions 9-12 refer to aqueous solutions containing 1: 1 mole ratios of the following pairs of substances. Assume all concentrations are 1 М. (А) NH 3 and NH4CI (В) Н3РО4 and NаН2РО4 (С) HCI and NaCI (D) NaOH and NН3 (Е) NН3 and НС2Н3O 2 (acetic acid) 9. Тhе solution with the lowest рН l О. The most nearly neutral solution l l. А buffer at а рН > 8 Questions 13-16 refer to the following descriptions of bonding in different types of solids. (А) Lattice of positive and negative ions held together Ьу electrostatic f orces �:­ (В) Closely packed lattice with de ос electrons throughout (С) Strong single covalent Ь inteпnolecular f orces (D) Strong multiple covalent bon (including n-bonds) with weak inteпnolecular forces r w��h strong (Е) Macromolecules held to sa:(1'_,f _ polar bonds fli� 13. Cesium chloride, CsCl(s) 14. Gold, Au(s) 15. Carbon dioxide, CO2(s) 16. 1. Methane, CH4(s) "" � - - �" Ouestions 17-18 refer to the following elements. (А) (В) (С) (D) (Е) Lithium Nickel Bromine Uranium Fluorine 17. Is а gas in its standard state at 298 К 18. Reacts with water to foпn а s , ong base PartB Directions: Each of the questions or incomplete statements below is followed Ьу five suggested answers or comple­ tions. Select the one that is Ьest in each case and then fill in the corresponding oval on the answer sheet. 19. Which of the following best describes the role of the spark from the spark plug in an automoblle engine? (А) The spark decreases the energy of activation for the slow step. (В) The spark increases the concentration of the volatile reactant. (С) The spark supplies some of the energy of activation for the combustion reaction. The spark provides а more favoraЫe activated complex (D) for the combustion reaction. (Е) The spark provides the heat of vaporization for the volatile hydrocarbon. 20. What mass of Au is produced when 0.0500 mol of Au2S3 is reduced completely with excess Н2 ? (А) 9.85 g (В) 19.7 g (С) 24.5 g (D) 39.4 g (Е) 48.9 g 21. When а solution of sodium chloride is vaporized in а flame, the color of the flame is (А) Ыuе (В) yellow (С) green (D) violet (Е) white 22. Of the following reactions, wblch involves the Jargest decrease (А) CaCO3 (s) ➔ CaO(s) + COz(g) (В) 2 CO(g) + O2(g) ➔ 2 CO2(g) (С) Pb(NO3)2(s) + 2 КI(s) ➔ РЫ2(s) + 2 КNO3 (s) (D) C3H8(g) + 5 Oz(g) ➔ 3 CO2(g) + 4 H2O(g) (Е) 4 La(s) + 3 Oz(g) ➔ 2 L a2O3(s) 2 2 24. The safest and most effective emergency· proce­ dure to treat an acid splash on skin is do wl\icp of the f ollowing immediately? \ { � Dry the affected area with paper towels Sprinkle the affected area with powdered Na2SOis) (С) Flush the affected area with watef apd then with а dilute NaOH solution l'J С J /@lush the affected area with water and then with а di]ute NaHCO3 solution (Е) Flush the affected area with water and then with а dilute vinegar solution 1/1 '1 23. А hot-air balloon, shown above, rises. Which of the following is the best explanation for this observation? (А) Тhе pressure оп the walls of the balloon increases with increasing temperature. (В) Тhе difference in temperature Ьetween the air inside and outside the balloon produces con­ vection currents. (С) Тhе cooler air outside the balloon pushes in on the walls of the balloon. (D) Тhе rate of diffusion of cooler air is less than that of warmer air. (Е) Тhе air density inside the balloon is less than that of the sштounding air. р Q т Time 25. The cooling curve for а pure substance as it changes from а liquid to а solid is shown аЬоvе. The solid and the liquid coexist at (А) (В) (С) (D) (Е) point Q only point R only all points on the curve Ьetween Q and S all points on the curve Ьetween R and Т по point on the curve 26. When the equation above is balanced and all coefficients are reduced to their lowest whole-numЬer terms, the coefficient for 02(g) is (А) 6 (В) 7 (С) 12 (D) 14 (Е) 28 27. Appropriate uses of а visiЫe-light spectrophotometer include which of the following? ''" -м.,.,,_,- I. concentration а solution Measuring the conductivity of а solution of КМnO4 � Determining which ions are present in а solution that may contain Na+, Mg2+, Ai3+ (А) Ionly (В) П only (С) ПIonly (D) Iand П only (Е) Iand Ш only в с "" �"' � - ll�011!imm I , 28. The melting point of MgO is higher than that of NaF. Explanations for this observation include which of the following? I. Mg2+ is more positively charged than Na+ . П. 02- is more negatively charged than р-. III. The 02- ion is smaller than the F- ion. (А) II only (В) I and П only (С) I and III only (D) II and III only (Е) I, П, and III о 11 сн 3 -с-сн 2 -сн3 29. The organic compound represented above is an example of (А) an organic acid (В) an alcohol (С) an ether (D) an aldehyde (Е) а ketone -Z.. ,1-I 1 H2Se(g) + 4 02Fig) ➔ SeF6(g) + 2 НF(g) + 4 O2(g) 30. Which of the following is true regarding the reaction represented above? (А) The oxidation number of О does not change. (В) The oxidation number of Н changes from -1 to +1. (С) The oxidation numЬer of F changes from +1 to -1. (D) The oxidation number of Se changes from -2 to +6. (Е) It is а disproportionation reaction for F. is the temperature of an aqueous solution ° ° 20 С to 90 С, which of the following statements is true? (А) (В) (С) (D) (Е) The density of the solution remains unchanged. The molarity of the solution remains unchanged.N° The molality of the solution remains unchanged. ._/1/\(L -::,., The mole fraction of solute decreases. The mole fraction of solute increases. llft... "' ё{, ,, 32. Types of hybridization ex.hiЬited Ьу the С atoms in propene, СН3СНСН2 , include which of the following? I. sp П. sp2 III. sp3 (А) Ionly (В) Ш only (С) Iand П only (D) IIand IIIonly (Е) I, II, and III 33. А 1.0 L sample of an aqueous solution contains 0.10 mol of NaCl and 0.10 mol of СаС12. What is the minimum number of moles of AgNO3 that must Ье added to the solution in order to precipi­ tate all of the с1- as AgCl(s) ? (Assume that AgCI is insoluЫe .) (А) (В) (С) (D) (Е) 0.Юmol 0.20 mol 0.ЗOmol 0.40 mol 0.60mol Ouestions 34-35 refer to an electrolytic cell that involves the foПowing half-reaction. С) AIFi- + 3 е- ➔ Al + 6 р34. Which of the foПowing occurs in the reaction? (А) AIFi- is reduced at the cathode . (В) Al is oxidized at the anode. (С) Aluminum is converted from the-3 oxi- фttion state to the О oxidation state. (D) р- acts as а reducing agent. (Е) р- is reduced at the cathode. 35 . А steady cuпent of 10 amperes is passed through an aluminum-production cell for 15 minutes. Which of the following is the correct expression for calculating the number of grams of aluminum produced? ( 1 faraday = 96,500 coulombs) (10) (15) (96,500) (А ) g (27) (60) (В) (10) (15) (27) g (60) (96,500) (С) (10) (15) (60) (27) g {96,500) (3) (D) (96,500) (27) g (10) (15) (60) (3) (Е) (27) (3) g (96,500) (10) (15) (60) �� -GO ON 1'0 ТНЕ- NEX1' PAGE - а 4 Experiment Initial [NO] (mol L -1) Initial [02 ] (mol L-1) 1 0.10 0.10 2 0.20 0.10 3 0.20 0.40 Initial Rate of Formation of NO2 (mol L-1s-1) 2.5 х 10-4 5.0 х 10-4 8.0 х 10-3 36. The initial-rate data in the tаЫе above were obtained for the reaction represented below. What is the experimental rate law for the reaction? 2 NO(g) + O 2 (g) ➔ NO 2 (g) (А) Rate = k[NO][O2] (В) Rate = k[NO][O 2 ]2 (С) Rate = k[NO]2 [0 2 ] (D) Rate = k[NO]2 [O 2 ]2 (Е) Rate = k ���1 Ionization Ener.Eries for element Х (kJ mоГ1 ) First Second Third Fourth Fifth 580 1,815 2,740 11,600 14,800 37. The ionization energies for element Х are listed in the tаЫе above. Оп the basis of the data, element Х is rnost likely to Ье (А) (В) (С) (D) (Е) Na Mg AI Si р 38. А molecule or an ion is classified as а Lewis acid if it (А) (В) (С) (D) (Е) accepts а proton from water accepts а pair of electrons to forrn а bond donates а pair of electrons to forrn а bond donates а proton to water has resonance Lewis electron-dot structures 41. After the equШbrium represented above is established, some pure 0 2 (g) is injected into the reaction vessel at constant ternperature. After equilibrium is reestaЫished, which of the fol­ lowing has а lower value cornpared to its value ·at the original equilibrium? (А) Keq for the reaction (В) The total pressure in the reaction vessel Temperature (0С) 39. The phase diagram for а pure substance is shown above. Which point оп the diagram corresponds to the equilibrium between the solid and liquid phases at the normal melting point? (А) А (В) В (С ) С (D) D (Е ) Е 40. 0f the following molecules, which has the largest dipole moment? (А) СО (В) СО2 (С) 02 (D) HF (Е) F2 (С) The amount of S0 3 (g) in the reaction vessel (D) The amount of 0 2 (g) in the reaction vessel (Е) The amount of S0 2 (g) in the reaction vessel а с i?'fi."41.,.;;"'"%-1'':t"'Ji"'�-""""" " М\а:))k� " �mf:}11i�m 1 � он-(аq) + .1.. NHз(g) 42. When the equation above is balanced and all coefficients reduced to lowest whole­ number terms, the coefficient for он-(аq) is (А) (В) (С) (D) (Е) 1 2 3 4 6 43. А sample of 61.8 g of Н3 ВО3, а weak acid, is dissolved in 1,000 g of water to make а 1.0-molal solution. Which of the following would Ье the Ьest procedure to determine the molarity of the solution? (Assume no additional information is � availaЬle.) (А) (В) (С) (D) (Е) Titration of the solution with standard acid Measurement of the рН with а рН meter Determination of the boiling point of the solution Measurement of the total volume of the solution Measurement of the specific heat of the solution 44. А rigid metal tank contains oxygen gas. Which of the following applies to the gas in the tank when additional oxygen is added at constant temperature? (1() The volume of the gas increases. .(В) Тhе pressure of the gas decreases. (С) Тhе average speed of the gas molecules remains the same. .(.0) The total number of gas molecu)es remains the same. .fE) The average distance between the gas molecules increases. 45. What is the н +(аq) concentration in 0.05 М HCN(aq) ? (The Ка for HCN is 5.0 х 10- 10.) (А) 2.5 х 10-11 М (В) 2.5 х 10-io М (С) 5.0 х 10- 10 М (D) 5.0 х ю- 6 М (Е) 5.0 х 10-4 М 46. Which of the following occurs when excess concentrated NH3(aq) is mixed thoroughly with 0.1 М Cu(NO3)2(aq) ? (А) (В) (С) (D) (Е) А dark red precipitate forms and settles out. Separate layers of immisciЫe liquids form with а Ыuе layer on top. Тhе color of the so)ution tums from light Ыuе to dark Ыuе. BubЬles of ammonia gas f orm. Тhе рН of the solution decreases. � )!, =" 1 1 73. The volume of distilled water that should Ье added to 10.0mL of 6.00 М HCl(aq) in order to prepare а 0.500 М HCl(aq) solution is approximately (А) 50.0mL (В) 60.0mL (С) 100.mL (D) 110.mL (Е) 120.mL 74. Which of the following gases deviates most from ideal behavior? (А) SO2 (В) Ne (С) СН4 (D) N2 (Е) Н2 75. Which of the following pairs of liquids forms the solution that is most ideal (most closely follows Raoult's law) ? (А) C8H 18(l) and H2O(l) (В) CH3CH2CH2OH(l) and H2O(l) (С) CH3CH2CH2OH(l) and C8H 18(l) (D) C 6H 1 il) and C8H 18(l ) (Е) H2S0il) and Н20(1)