The highest viscosity is observed for which of the following liquid/temperature combinations? Group of answer choices C6H14 at 299 K C6H14 at 275 K HOC4H8OH at 275 K C5H12 at 299 K HOC4H8OH at 299 K

Classify each of the following statements as true or false. a Intermolecular attractions are stronger in liquids than in gases. b Substances with weak intermolecular attractions generally have low vapor pressures. c Liquids with high molar heats of vaporization usually are more viscous than liquids with low molar heats of vaporization. d A substance with a relatively high surface tension usually has a very low boiling point. e All other things being equal, hydrogen bonds are weaker than induced dipole or dipole forces. f Induced dipole forces become very strong between large molecules. g Other things being equal, nonpolar molecules have stronger intermolecular attractions than polar molecules. h The essential feature of a dynamic equilibrium is that the rates of opposing changes are equal. i Equilibrium vapor pressure depends on the concentration of a vapor above its own liquid. j The heat of vaporization is equal to the heat of fusion, but with opposite sign. k The boiling point of a liquid is a fixed property of the liquid. l If you break shatter an amorphous solid, it will break in straight lines, but if you break a crystalline solid, it will break in curved lines. m Ionic crystals are seldom soluble in water. n Molecular crystals are nearly always soluble in water. o The numerical value of heat of vaporization is always larger than the numerical value of heat of condensation. p The units of heat of fusion are kJ/gC. q The temperature of water drops while it is freezing. r Specific heat is conerned with a change in temperature.

The density of liquid NH3 is 0.64 g/mL; the density of gaseous NH3 at STP is 0.0007 g/mL. Explain the difference between the densities of these two phases.

In terms of the kinetic molecular theory, in what ways are liquids similar to solids? In what ways are liquids different from solids?

On the basis of intermolecular attractions, explain the differences in the boiling points of n butane (1 C) and chloroethane (12 C), which have similar molar masses.

What are the two ways in which the escape of high-energy molecules from the surface of a liquid during the process of evaporation affects the liquid?

Define the following and give an example of each: (a) dispersion force (b) dipole-dipole attraction (c) hydrogen bond

Trichloroethane, C2H3Cl3, is the active ingredient in aerosols that claim to stain-proof men's ties. Trichloroethane has a vapor pressure of 100.0 mm Hg at 20.0C and boils at 74.1C. An uncovered cup (12pint) of trichloroethane (d=1.325g/mL) is kept in an 18-ft3 refrigerator at 39F. What percentage (by mass) of the trichloroethane is left as a liquid when equilibrium is established?

The surface tension and viscosity values for diethyl ether, acetone, ethanol, and ethylene glycol are shown here. (a) Explain their differences in viscosity in items of the size and shape of their molecules and their IMFs. (b) Explain their differences in surface tension in items of the size and shape of their molecules and their IMFs:

5-106 The normal boiling point of hexane, C6H14, is 69°C, and that of pentane, C5H12, is 36°C. Predict which of these compounds has a higher vapor pressure at 20°C.