Vapor Pressure and Boiling

Oxygen, nitrogen, and fluorine bond with hydrogen to form molecules. These molecules are attracted to each other by (A) coordinate covalent bonds   (B) hydrogen bonds (C) electrovalent bonds (D) ionic bonds The unusually high boiling point of H₂O is primarily due to the presence of (A) ionic bonds (B) molecule-ion attractions (C) hydrogen bonds (D) intermolecular forces Which compound has the highest normal boiling point?   (A) H₂Te (B) H₂S (C) H₂O (D) H₂Se Which attractions allow molecules of krypton to exist in the solid phase? (A) ionic bonds (B) molecule-ion forces (C) weak intermolecular forces (D) covalent bonds   As the distance between two molecules increases, the magnitude of the intermolecular forces of attraction between them (A) increases (B) remains the same (C) decreases Argon has a higher boiling point than neon because argon has (A) stronger intermolecular forces of attraction (B) weaker intermolecular forces of attraction (C) fewer electrons in its 2nd principal energy level (D) more electrons in its outermost principal energy level   Which noble gas has the lowest normal boiling point? (A) Kr (B) Xe (C) Ne (D) Ar The table below shows boiling points for the elements listed. | Element | Normal Boiling Point (°C) | |---|---| | Fluorine | -188.1 | | Chlorine | -34.6 | | Bromine | +58.8 | | Iodine | +184.4 | Which of the following statements best explains the pattern of boiling points relative to molecular size?   (A) Weaker hydrogen bonds occur in larger molecules.   (B) Stronger intermolecular forces occur in larger molecules. (C) Weaker intermolecular forces occur in larger molecules. (D) Stronger hydrogen bonds occur in larger molecules. 10. At 25°C, I₂ is a solid but F₂ is a gas. This is most likely due to the fact that * (A) I₂ molecules have stronger intermolecular attractions * (B) F₂ molecules have stronger intermolecular attractions * (C) I₂ is a dipole, but F₂ is not * (D) F₂ is a dipole, but I₂ is not   11. Which sequence of Group 18 elements demonstrates a gradual decrease in the strength of intermolecular forces of attraction?   * (A) Kr(l), Xe(l), Ar(l), Ne(l) * (B) Ne(l), Ar(l), Kr(l), Xe(l) * (C) Ar(l), Kr(l), Ne(l), Xe(l) * (D) Xe(l), Kr(l), Ar(l), Ne(l) 12. In an experiment, a student determined the normal boiling points of four unknown liquids. The collected data were organized into the table below.   | Unknown Liquids | Normal Boiling Points (°C) | |---|---| | A | 10 | | B | 35 | | C | 78 | | D | 100 | **What unknown liquid has the weakest attractive forces between its molecules?** * (A) A * (B) B * (C) C * (D) D 13. Which substance will sublime at 298 K? * (A) CO₂(s) * (B) KOH(s) * (C) Si(s) * (D) Al(s) 14. In an aqueous solution of an ionic salt, the oxygen atom of the water molecule is attracted to the * (A) positive ion of the salt, due to oxygen's partial negative charge * (B) negative ion of the salt, due to oxygen's partial positive charge * (C) positive ion of the salt, due to oxygen's partial positive charge * (D) negative ion of the salt, due to oxygen's partial positive charge 15. When NaCl(s) is dissolved in H₂O(l), the sodium ion is attracted to the water molecule's * (A) negative end, which is oxygen * (B) negative end, which is hydrogen * (C) positive end, which is oxygen * (D) positive end, which is hydrogen 16. Which diagram best illustrates the ion-molecule attractions that occur when the ions of NaCl(s) are added to water? * [Four diagrams showing different arrangements of water molecules and Na+ and Cl- ions]