Use the phase diagram of Substance X below to find the temperature at which X turns to a gas, if the pressure above the solid is 1.6 atm. pressure (atm) 20- solid liquid 100 200 gas temperature (K) Note: your answer must be within 12.5 °C of the exact answer to be graded correct.

Krypton, Kr, has a triple point at 169C and 133 mmHg and a critical point at 63C and 54 atm. The density of the solid is 2.8 g/cm3, and the density of the liquid is 2.4 g/cm3. Sketch a rough phase diagram of krypton. Circle the correct word in each of the following sentences (and explain your answers). a Solid krypton at 130 mmHg (melts, sublimes without melting) when the temperature is raised. b Solid krypton at 760 mmHg (melts, sublimes without melting) when the temperature is raised.

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.

Consider the following data for xenon: Triple point: 121C, 280 torr Normal melting point: 112C Normal boiling point: 107C Which is more dense, Xe(s) or Xe(l)? How do the melting point and boiling point of xenon depend on pressure?

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?

What phase changes will take place when water is subjected to varying pressure at a constant temperature of 0.005 C? At 40 C? At 40 C?

ou seal a container half-filled with water. Which best describes what occurs in the container? Water evaporates until the air becomes saturated with water vapor; at this point, no more water evaporates. Water evaporates until the air becomes overly saturated (supersaturated) with water, and most of this water recondenses; this cycle continues until a certain amount of water vapor is present, and then the cycle ceases. The water does not evaporate because the container sealed. Water evaporates, and thou water evaporates and recondenses simultaneously and continuously. The water evaporates until it is eventually all in vapor form. stify your choice, and for choices you did not pick, explain what is wrong with them.

8.51 Suppose that three unknown pure substances are liquids at room temperature. You determine that the boiling point of substance A is 53°C, that of substance B is 117°C, and that of substance C is 77°C. Based on this information, rank the three substances in order of their vapor pressures at room temperature.

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.

Which of the following substances can be liquefied by applying pressure at 25C? For those that cannot, describe the conditions under which they can be liquefied. Substance Critical Temperature Critical Pressure Sulfur dioxide, SO2 158C 78 atm Acetylene, C2H2 36C 62 atm Methane. CH4 82C 46 atm Carbon monoxide, CO 140C 35 atm