(HOCH2CH2OH) is less viscous than glycerine
(HOCH2CHOHCH2OH), but more viscous than ethyl
20. Consider the following substances: sodium fl uoride
(NaF), chlorine monofl uoride (ClF), hydrogen fl uoride
(HF), and fluorine (F2 ). (a) What type of particles does
each substance have? (b) What type of intermolecular
attractive forces hold the particles together in each
substance? The table below lists the melting point (mp),
boiling point (bp), density (D), and solubility in water of
each of these substances.
mp, °C bp, °C D, g/L Solubility
NaF 993 1700 2558 (s) 4.13 g/100 g
ClF 2156 2100 2.43 (g) violent reaction
HF 284 20 0.922 (g) miscible
F2 2220 2188 1.69 (g) mild reaction
(c) Based on this information, determine the relative
strengths of the forces holding the particles together.
(d) List the intermolecular attractive forces in order of
25. Within each group, assign each of the boiling points
to the respective substances on the basis of intermolecular
forces. (a) N2, HCN, C2H6: 2196°C, 289°C, 26°C;
(b) H2, HCl, Cl2: 235°C, 2259°C, 285°C.
26. ■ What type of intermolecular forces must be overcome
in converting each of the following from a liquid to a gas?
(a) CO2; (b) NH3; (c) CHCl3; (d) CCl4.
57. Toluene, C6H5CH3, is a liquid used in the manufacture of TNT. Its normal boiling point is 111.0°C, and its molar
heat of vaporization is 35.9 kJ/mol. What would be the
vapor pressure (torr) of toluene at 75.00°C?
73. ▲ ■ (a) How many triple points are there for sulfur? (b) Indicate the approximate pressure and temperature at
each triple point. (c) Which phases are in equilibrium
at each triple point?
81. ■ Based only on their formulas, classify each of the
following in the solid state as a molecular, ionic, covalent (network), or metallic solid: (a) Au, (b) NO2, (c) CaF2,
(d) SF4, (e) Cdiamond.
93. A certain metal has a specifi c...