Exam 2 Review Ammonia, NH3, is used as a refrigerant. At its boiling point of –33 °C, the standard enthalpy of vaporization of ammonia is 23.3 kJ/mol. What is the change in enthalpy when 53.9 g of ammonia is condensed at –33 °C? A. 7.36 kJ B. -7.36 kJ C. -23.3 kJ D. -73.7 kJ E. 73.7 kJ As pure molecular solids, which of the following exhibits dipole-dipole intermolecular forces: PH3, SO3, HCl, and CO2? A. PH3 and HCl B. PH3 only C. SO3 and CO2 D. SO3, HCl, and CO2 E. HCl only The predominant intermolecular attractive force in N2 is: A. Covalent B. induced dipole-induced dipole C. Dipole-dipole D. Ionic E. dipole-induced dipole Which action(s) will decrease the equilibrium concentration of an inert gas (such as N2) in water? 1. decreasing the temperature of the water 2. increasing the volume of water 3. decreasing the pressure of the gas above the liquid A. 1, 2, and 3 B. 1 and 3 C. 1 only D. 2 only E. 3 only What is the H3O+ concentration in 4.15E-3 M NaOH(aq) at 25 °C? (Kw = 1.01E-14) A. 4.19E-17 M B. 4.11E+11 M C. 9.90E+13 M D. 2.43E-12 M E. 3.53E-12 M Which equation depicts aqueous hydrogen sulfide, behaving as a Brønsted-Lowry acid in water? A. H2S(aq) + 2 OH–(aq) SO2(aq) + 2 H2(g) B. HS–(aq) + H3O+(aq) H2S(aq) + H2O( ) C. H2S(aq) + H3O+(aq) H3S+(aq) + H2O( ) D. HS–(aq) + H2O( ) HSO+(aq) + H2(s) E. H2S(aq) + H2O( ) HS–(aq) + H3O+(aq) Which of the following statements concerning intermolecular forces is/are CORRECT? 1. Dipole-dipole attractions occur in all molecules that contain polar bonds, regardless of whether the molecule has a dipole. 2. Induced dipole/induced dipole forces exist in all molecular solids. 3. Hydrogen bonding only occurs in molecules containing OH bonds. A. 1, 2, and 3 C. 1 only E. 2 only B. 3 only D. 1 and 2Exam 2 Review In the following net ionic equation, identify the Bronsted-Lowry acid: NO2- (aq) + HS- (aq) HNO2 (aq) + S2- (aq) A. NO2- B. HS- C. S2- D. HNO2 What intermolecular force or bond is primarily responsible for the solubility of CH3OH in water? A. ionic bonding B. ion-dipole force C. hydrogen bonding D. covalent bonding E. dipole-dipole force What is the molar mass of a nonpolar molecular compound if 9.02 grams dissolved in 52.0 grams benzene begins to freeze at 2.15°C? The freezing point of pure benzene is 5.50 °C and the freezing point depression constant, Kfp, is –5.12 °C/m. A. 3.77 g/mol B. 209 g/mol C. 265 g/mol D. 153 g/mol E. 297 g/mol Which of the following molecules is expected to form hydrogen bonds in the pure liquid or solid phase: ethanol (CH3CH2OH), acetic acid (CH3CO2H), acetaldehyde (CH3CHO), and dimethyl ether (CH3OCH3)? A. acetaldehyde only B. ethanol and acetic acid C. acetaldehyde and dimethyl ether D. ethanol only E. ethanol and dimethyl ether The Henry's law constant for N2 in water at 25 °C is 6.0E-4 mol/kg×bar. What is the equilibrium concentration of N2 in water when the partial pressure of N2 is 401 mm Hg? (760 mm Hg = 1 atm = 1.013 bar) A. 1.15E-3 m B. 3.21E-4 m C. 1.14E-3 m D. 3.17E-4 m E. 0.241 m The conjugate base of OH– is ____. A.OH+ B. O2– C.H3O+ D.OH– E. H+ Which of the following liquids will be miscible with water in any proportions: ethanol (CH3CH2OH), carbon tetrachloride (CCl4), hexane (C6H14), and/or formic acid (HCO2H)? A. carbon tetrachloride and formic acid B. carbon tetrachloride and hexane C. ethanol and formic acid D. ethanol and carbon tetrachloride E. ethanol, carbon tetrachloride, and hexaneExam 2 Review What is the mole fraction of water in a solution that is 25.4 % by weight ethylene glycol? The molar mass of ethylene glycol, HOCH2CH2OH, is 62.07 g/mol. A. 9.00E-2 B. 0.746 C. 0.910 D. 2.94 E. 10.1 Which of the following liquids has the largest enthalpy of vaporization? A. C4H10 B. C5H12 C. C2H6 D. C3H8 E. C6H14 Ideally, colligative properties depend only on the A. molar masses of the solute particles in a solution. B. relative numbers of solute and solvent particles in a solution. C. hydrated radii of the molecules or ions dissolved in a solution. D. partial pressure of the gases above the surface of a solution. E. density of a solution. Select the one best statement: Boiling point elevation..... A. occurs only when ionic solids are present B. occurs only at sea level C. occurs only for molecular solutes D. results from a reduction in the vapor pressure of the solution E. is the change in boiling point observed when one goes to a higher elevation When a glass tube with a small diameter is placed in water, the water rises in the tube. This is known as ______________ action. A 12.6 meter by 13.1 meter pool of water has a depth of 2.85 meters. What mass of silver ion is present in the reservoir if the concentration of silver ion is 0.180 ppm? (1 m3 = 1000 L; assume the density of the solution is 1.00 g/mL) A. 0.847 g B. 7.13E-2 g C. 84.7 g D. 8.47E-2 g E. 1.80E-4