boiling point? (Consider possible hydrogen bondings)     Select one: a.   C2H5SH b.

Why do liquids have a vapor pressure? Do all liquids have vapor pressures? Explain. Do solids exhibit vapor pressure? Explain. How does vapor pressure change with changing temperature? Explain.

Consider the following formulas for n-pentane and neopentane: CH3CH2CH2CH2CH3 -Pentane Both compounds have the same overall formula (C5H12, molar mass = 72.15 g/mol), yet n-pentane boils at 36.2C whereas neopentane boils at 9.5C. Rationalize the differences in the boiling points between these two nonpolar compounds.

Which of the following statements about intermolecular forces is( are) true? a. London dispersion forces are the only type of intermolecular force that nonpolar molecules exhibit. b. Molecules that have only London dispersion forces will always be gases at room temperature (25C). c. The hydrogen-bonding forces in NH3 are stronger than those in H2O. d. The molecules in SO2(g) exhibit dipole-dipole intermolecular interactions. e. CH3CH2CH3 has stronger London dispersion forces than does CH4.

Trichloroethane, C2H3Cl3 is used as a degreaser (solvent for waxes and oils). Its density is 1.435 g/mL and its vapor pressure at 20C is 124 mm Hg. (a) How many mL will vaporize in an evacuated 1.50-L flask at 20C? (b) A 3.00-mL sample is poured into an evacuated 1.5-L flask at 20C. Will all the liquid vaporize? If not, what is the pressure in the flask? (c) A similar 3.00-mL sample is poured into an evacuated 20.00-L flask at 20C. What physical state(s) is/are in the flask?

Why do the boiling points of the noble gases increase in the order HeNeArKrXe?

How do ionic solids differ in structure from molecular solids? What are the fundamental panicles in each? Give two examples of each type of solid and indicate the individual particles that make up the solids in each of your examples.