Intermolecular Forces Questions

1331 – CHAPTER 11 QUESTIONS Intermolecular Forces 1. The stronger the intermolecular forces in a substance (A) (C) the higher the boiling point. the higher the vapor pressure. 2. Which substance has the highest boiling point? (A) CH4 3. Which one of these solid substances has a crystal structure containing discrete molecules? (A) dry ice 4. Which group of substances is arranged in order from the highest to the lowest melting point? (A) HF>H2>NaF 5. Which has the highest boiling point? (A) Ar 6. Arrange KCl, NH3, and CH4 in order of increasing boiling point. (A) CH4< KCl< NH3 7. Which has the highest molar heat of vaporization? (A) S8 8. Which of the following properties does not increase with increasing intermolecular forces (A) viscosity 9. When liquid bromine is cooled to form a solid, which of the following types of solid would it form? A. atomic 10. Which one of the following substances does not exist in the indicated solid type? A. D. graphite – network covalent B. NaCl – ionic E. 11. Neon condenses due to (B) (B) He (B) (B) B. (C) quartz (B) (B) (B) (D) (C) the lower the boiling point. the smaller the deviation from ideal gas behavior. HF (D) graphite NaF>H2>HF Kr (C) (C) Xe (C) (D) metallic C. melting point molecular D (D) (D) NH3< CH4< KCl BaF2 (D) ionic E. vapor pressure covalent network Na – metallic C. SiO2 - molecular diamond – network covalent 1 NaF>HF>H2 Ne CH4< NH3< KCl Ar heat of vaporization (C) silver bromide HF>NaF>H2 (D) (B) NH3< KCl< CH4 (C) H2O (D) Cl2 (A) (C) dipole-dipole forces hydrogen bonding (B) (D) London dispersion forces covalent bonding 12. Which of the following molecules will not form hydrogen bonds? O H3C (A) CH2 C (B) OH HF H O H3C (C) CH2 C CH3 (D) H3C CH2 N CH3 13. Ammonia’s unusually high melting point is the result of (A) (C) dipole-dipole forces hydrogen bonding 14. Octane is a component of fuel used in internal combustion engines. The dominant intermolecular forces in octane are (A) (C) dipole-dipole forces hydrogen bonding 15. In hydrogen iodide __________________ are the most important intermolecular forces. (A) (C) dipole-dipole forces hydrogen bonding 16. When the electron cloud of a molecule is easily distorted, the molecule has a high _____________. (A) polarity (B) (D) (B) (D) (B) (D) (B) polarizability London dispersion forces covalent bonding London dispersion forces covalent bonding London dispersion forces covalent bonding (C) dipole moment (D) van der Waals radius 17. Which of the following atoms should have the greatest polarizability? (A) F 18. Which of the following atoms should have the smallest polarizability? (A) Si (B) (B) Br S (C) (C) Po Te (D) (D) Pb Bi 2 19. The strongest intermolecular interactions between pentane (C5H12) molecules arise from (A) (C) dipole-dipole forces hydrogen bonding 20. The strongest intermolecular interactions between ethyl alcohol (CH3CH2OH) molecules arise from (A) (C) dipole-dipole forces hydrogen bonding 21. The strongest intermolecular interactions between hydrogen sulfide (H2S) molecules arise from (A) (C) dipole-dipole forces hydrogen bonding 22. The strongest intermolecular interactions between hydrogen fluoride (HF) molecules arise from (A) (C) dipole-dipole forces hydrogen bonding 23. Which of the following will form hydrogen bonds between molecules? (A) (C) (CH3)3N CH3CH2—OH 24. Which of the following pairs is arranged with the particle of higher polarizability listed first? (A) Se2-, S2- 25. Which of the following pairs is arranged with the particle of higher polarizability listed first? (A) CCl4, CI4 26. Which of the following should have the highest boiling point? (A) CF4 27. Which of the following should have the lowest boiling point? (A) C5H12 28. Which of the following has a boiling point which does not fit the general trend? (A) NH3 (B) (D) (B) (D) (B) (D) (B) (D) (B) (D) (B) (B) (B) (B) (B) I, I- C6H14 PH3 London dispersion forces covalent bonding London dispersion forces covalent bonding London dispersion forces covalent bonding CH3—O—CH3 CH3CH2—F (C) H2O, H2Se CCl4 London dispersion forces covalent bonding Mg2+, Mg (C) (C) (C) (C) (D) Br, I C6H14, C4H10 (D) CBr4 C8H18 AsH3 3 (D) (D) (D) NH3, NF3 CI4 C10H22 SbH3 29. Select the pair of compounds in which the substance with the higher vapor pressure at a given temperature is listed first. (A) (C) C7H16, C5H12 H2O, H2S 30. Which of the following should have the highest surface tension at a given temperature? (A) CF4 31. The energy needed to increase the surface area of a liquid by one square meter is (A) (C) capillary action viscosity 32. When the adhesive forces between a liquid and the walls of a capillary tube are greater than the cohesive forces within the liquid (A) the liquid level in a capillary tube will rise above the surrounding liquid and the surface in the capillary tube will have a convex meniscus the liquid level in a capillary tube will rise above the surrounding liquid and the surface in the capillary tube will have a concave meniscus the liquid level in a capillary tube will drop below the surrounding liquid and the surface in the capillary tube will have a convex meniscus the liquid level in a capillary tube will drop below the surrounding liquid and the surface in the capillary tube will have a concave meniscus (B) (C) (D) (B) (D) (B) CCl4 (C) (B) (D) CCl4, CBr4 CH3CH2OH, CH3—O—CH3 (D) CBr4 CI4 surface tension cohesion 33. The resistance of a liquid to flow is (A) surface tension 34. Which of the following factors contributes to a low viscosity for a liquid? (A) (C) low temperature hydrogen bonding 35. Which of the following liquid substances would you expect to have the lowest surface tension? (A) Pb 36. Which of the following liquids is likely to have the highest surface tension? (A) Br2 (B) (B) (B) CH3OCH3 C8H18 capillary action (B) (D) (C) (C) (C) viscosity (D) adhesion spherical molecular shape high molecular weight HOCH2CH2OH (D) (D) CH3OCH3 4 H2O Pb (E) (E) CH3CH2OH CH3OH Phase Changes 37. How much energy is released when 100.0 g of diethylether is cooled from 53.0 °C to 10.0 °C? Boiling point = 34.5 °C; ΔHvap = 351 J/g; specific heat of liquid = 3.74 J/g K; specific heat of gas = 2.35 J/g K (B) 13.1 kJ (C) 48.6 kJ 10.1 kJ 38. Examine the following phase diagram and identify the feature represented by point A. A. melting point B. 39. What are the changes in phase going from points A to B to C to D critical point C. 16.1 kJ (D) (A) triple point D. sublimation point P B A D C T A. C. E. melting, vaporization, deposition submination, freezing, melting melting, sublimation, deposition B. D. vaporization, freezing, sublimation freezing, sublimation, vaporization 5