Day-1-exam-1.docx

1. The mass of a proton or neutron is approximately _______ times that of an electron. A. 1,736 B. 1,900 C. 1,700 D. 1,836 2. Deuterium or heavy hydrogen has an atomic no. of 1 and a mass of A. 3 B. 2 C. 1 D. 4 3. Which of the following is the lightest? A. alpha particle B. beta particle C. proton D. hydrogen 4. The volume of an ideal gas is zero at ________. A. 0˚C B. -45˚F C. -273 K D. -273˚C 5. Of the following gases, _________ will have the greatest rate of effusion at a given temperature. A. NH3 B. CH4 C. Ar D. HBr 6. Of the following gases, the one with the greatest density at STP is: A. CH4 B. NH3 C. Ne D. H2 7. Which of the following is the reason that metals conduct electricity? A. The metal atoms are close together B. There are no empty spaces in metal structures C. Electrons in the structure can move freely D. Electrons and protons in the structure can move freely 8. The basic repeating structural unit of a crystal lattice is the A. unit cell B. atom C. molecule D. atomic cluster 9. In the hexagonal close-packed structure, each atom has a coordination number of A. 4 B. 6 C. 8 D. 12 10. In diamond, each carbon is covalently bonded to _______ other carbon atoms A. 2 B. 3 C. 4 D. 6 11. Magnesium cannot displace from solution the ions of A. sodium B. lead C. copper D. gold 12. What is the degree of freedom of a system consisting of a gaseous mixture of carbon dioxide and nitrogen? A. 0 B. 1 C. 2 D. 3 13. How many components are necessary to define the following equilibrium? CaCO3(s) CaO(S) +CO2(g) A. 0 B. 1 C. 2 D. 3 14. Which of the following will have the largest size? A. Br B. IC. I D. F 15. As the atomic number increases in a group, the chemical properties A. change B. stay roughly the same C. decrease D. stabilize 16. Which does not belong to the group? A. copper B. silicon C. boron D. arsenic 17. Which of the following is a semi-conductor? A. B B. Ge C. Si D. all of these 18. Describe the geometry of CH2Cl2, dichloromethane. Is it a polar or a nonpolar molecule? A. pyramidal, polar B. tetrahedral, polar C. pyramidal, nonpolar D. tetrahedral, nonpolar 19. The bond angle in CH4 is approximately A. 90˚ B. 109˚ C. 105˚ D. 120˚ 20. What can be the molar shape of BCl3? A. square planar B. planar C. triangular D. linear 21. Hardness of diamond is due mainly to a large amount of A. covalent bond B. hydrogen bond C. ionic bond D. sigma bond 22. An element consist of 60.10% of an isotope with an atomic mass of 68.926 amu and 39.90 % of an isotope with an atomic mass Of 70.925 amu. What is the atomic weight of the element? A. 34.86 amu B. 13.13 amu C. 41.42 amu D. 69.72 amu 23. How many electrons are in 0.01 g of gold? A. 3 E 19 B. 2.4 E 21 C. 5E -5 D. 3.2 E 24 24. What is the mass of the electron? A. 1.22 E -24 kg B. 1.22 E -22 kg C. 1.22E -18 kg D. 9.11 E -31 kg

25. Give the mass empirical formula of the following compound if a sample contains 57.8%C, 36%H, and 38.6%O by mass. A. C2HO B. C4H3O2 C. C8H6O4 D. C12H9O6 26. A compound has the empirical formula CH and a molecular mass of 78. What is the molecular formula of the compound? A. C2H2 B. C3H3 C. C4H4 D. C6H6 27. Determine the empirical formula of a compound that contains 52.9% aluminum and 47.1% oxygen A. AlO B. Al2O3 C. Al3O2 D. Al4O6 28. An element X is found to combine with oxygen to form a compound with the molecular formula X4O6. If 8.4 g of the element X combine with 6.50 g of oxygen, the atomic weight of the element is A. 24 B. 50.4 C. 118.7 D. 62.03 29. According to the label, a bottle of vodka has a 40% by volume concentration. This means the vodka contains 40 mL of pure alcohol A. in each 140 mL of vodka B. to every 100 mL of water C. to every 60 mL of vodka D. mixed with water to make a 100 mL vodka 30. The density of a solution that is 20.0% by weight HClO4 is 1.138 g/ml. Calculate the molarity of the HClO4. A. 0.442 B. 1.99 C. 3.45 D. 2.26 31. Indicate the concentration of each on or molecule present in a 0.25 M CaBr2 solution. A.0.25 M Ca2+, 0.25 M Br- C. 0.25 M Ca2+, 0.50 M BrB. 0.25 M CaBr2 D. 0.50 M Ca2+, 0.50 M Br32. What mass of sodium carbonate is needed to make 120 mL of a 1.5 M solution? A. 295 g B. 75 g C. 19 g ` D. 589 g 33. The coolant in a car mobile is ethylene glycol, C2H6O2 by mass. It has a density of 1.06 g/ml. What is the molarity of ethylene glycol solution? A. 4.22 M B. 5.44 M C. 7.88 M D. 8.55 M 34. A 1.038 M sucrose in water solution has a density of 1.1 g/mL. Calculate the molality of the solution. A. 1.22 B. 1.30 C. 1.39 D. 1.48 35. What is the normality of a solution of H2SO4 if it has a specific gravity of 1.84 and contains 95.0% H2SO4 by weight? A. 3.56 N B. 5.63 N C. 5.63 M D. 0.065 M 36. A 0.5 M solution of H2SO4 is the same as _______ H2SO4. A. 2 N B. 1 N C. 0.5 N D. 0.1 N 37. If 27 mL of water is added to 35 mL of 0.1 M solution of any substance, what is the molarity of the final solution? A. 0.56 M B. 5.6 M C. 0.056 M D. 0.065 M 38. Mixing 10 mL of a 2 M HCl solution with 20 mL of a 1 M HCl solution will result in a solution whose molarity is: A. 1.33 B. 1.5 C. 1.65 D. 1.75 39. A 2.5 g sample of groundwater was found to contain 5.4 microgram of Zn2+. What is the concentration Zn2+ in parts per million. A. 1.5 B. 2.2 C. 3.0 D. 3.7 40. A solution of HCl has a specific gravity of 1.12 and contains 23.81% HCl by weight. How many grams of HCl are present in each milliliter of the solution? A. 1.2 B. 12.6 C. 13.2 D. 0.27 41. A 1m3 sample of air was found to contain 80 micrograms per m3 of sulfur dioxide. The temperature and pressure were 25˚C and 103.193 kPa when the air sample was taken. What was the sulfur dioxide concentration in parts per million? A. 0.03 ppm B. 300 ppm C. 120 ppm D. 0.075 ppm 42. Mayonnaise and milk are example of: A. emulsion B. suspension C. colloid D. mixture 43. How many milliliters (STP) of oxygen and hydrogen will be liberated by 5 A flowing for 25 minutes through acidulated water?. A. 720 ml H2 and 400 ml O2 C. 870 ml O2 and 435 ml H2 B. 870 ml H2 and 435 ml O2 D. 720 ml O2 and 400 ml H2 44. Given 6 coulombs and time is 2 seconds, what is the current flow in amperes? A. 12 B. 3 C. 1/3 D. 24

45. How long must a current of 5 amperes pass through a 10 ohm resistor until a charge of 1200 coulombs passes through? A. 1 min B. 2 min C. 3 min D. 4 min 46. How long (in minutes) will it take to plate a piece of automobile molding with 1 g of chromium metal using a Cr3+ solution and a 2 A current. A. 46.4 B. 52.1 C. 58.5 D. 62.1 47. A current of electricity was passed through a series of cells containing AgNO3, CuSO4, and H2SO4 solutions for a period of 25 minutes. If the weight of the silver deposited was 0.5394 g, what would be the weight of the copper? A. 0.159 g B. 1.59 g C. 15.9 g D. 159 g 48. An aqueous solution of gold (III) nitrate is electrolyzed with a current of 0.555 ampere until 1.32 g of Au has been deposited on the cathode. If the atomic weight of Au is 197, determine the duration of the electrolysis. A. 65.43 min B. 23.67 min C. 58.28 min D. 60 min 49. What is the electric current in amperes if 7.25 g Ag is deposited at the cathode in 2.0 hr in the electrolysis of AgNO3(aq). A. 4.32 B. 54 C. 2.56 D. 1.32 50. Two charges at +2.0 E -9 C that are 3.0 mm apart repel each other with a force of A. 4 E -9 N B. 4 E -3 N C. 6 E 3 N D. 3.6 E 7 N 51. An open chamber rest on the ocean floor in 50 m of sea water (SG=1.03). The pressure in kilopascals that must be maintained inside to exclude water is nearest to A. 318 B. 431 C. 505 D. 661 52. The volume of a gas is 50 ml when the pressure is 1520 mm and the temperature is 0˚C.The volume becomes 25 ml when the temperature is raised to 546 ˚C and the pressure is changed. Calculate the final pressure. A. 9.120 mm B. 91.20 mm C. 912.0 mm D. 9120 mm 53. A sample of hydrogen occupies a volume of 2.5 L at atmospheric pressure and a temperature of 25.0˚C. If the gas is cooled at constant pressure to -200˚C, what will the volume be? A. 0.512 L B. 0.548 L C. 0.613 L D. 0.670 L 54. A volume of dry gas measures 85 ml at 21˚C and 758 mmHg. What volume would this gas occupy if collected over water at 755.5 mmHg at 25˚C? A. 85 ml B. 86.5 ml C. 89 ml D. 83.2 ml 55. What is the specific gravity of nitrogen at 80˚F and 745 mmHg compared to air at the same condition? A. 0.97 B. 0.91 C. 0.85 D. 0.82 56. A 620 mg ideal gas occupies 175 cc at STP. What is the molecular weight of the ideal gas? A. 56 B. 60 C. 65 D. 79 57. Given one molecule of CO2 what is the volume at STP? A. 1.094 x 10-20 L B. 0.00065 L C. 2.01 x 10-18 L D. 3.72 x 10-23 L 58. Solutions of hydrogen chloride in chlorobenzene obeys Henry’s Law. K=P/m=0.438 where P is given in the atmosphere and m is the molality. What is the partial pressure of HCl in mmHg over a 1% by weight solution of HCl in chlorobenzene? A. 74.4 B. 87.5 C. 92.1 D. 96.75 59. Calculate the temperature in ˚C that must be maintained in a gas carrier tank in the form of a horizontal cylinder with hemispherical heads if it carries 100 g of oxygen gas at 2000 Pa. the total length of the tank is 10 m and its diameter is 2 m. A. 1984 B. 1888 C. 1521 D. 1990 60. The density of a gas mixture of O2 and N2 is 1.1705 g/L at 27 ˚C and 750 mmHg. The % of N2 in the mixture is A. 70 % B. 68 % C. 30 % D. 32 %