Phase Diagram 4 1 3 Temperature Pressure

Referring to Figure 9.7, state what phase(s) is (are) present at (a) 1 atm, 10C. (b) 3 mm Hg, 20C. (c) 1000 mm Hg, 75C.

The types of intermolecular forces in a substance are identical whether it is a solid, a liquid, or a gas. Why then does a substance change phase from a gas to a liquid or to a solid?

he enthalpy (H)of vaporization of water is about seven times larger than water’s enthalpy fusion(41kJ/molvs.6kJ/mol). What does this tell us about the relative similarities among the solid, liquid, and gaseous states of water?

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.

Carbon tetrachloride, CCl4, has a vapor pressure of 213 torr at 40.C and 836 torr at 80.C. What is the normal boiling point of CCl4?

A special vessel (see Fig. 10.45) contains ice and supercooled water (both at 10C) connected by vapor space. Describe what happens to the amounts of ice and water as time passes.

The phase diagram for water over a relative narrow pressure and temperature range is given in Figure 9.19. A phase diagram over a considerably wider range of temperature and pressure (kbar) is given nearby. This phase diagram illustrates the polymorphism of ice, the existence of a solid in more than one form. In this case, Roman numerals are used to designate each polymorphic form. For example, Ice I, ordinary ice, is the form that exists under ordinary pressures. The other forms exist only at higher pressures, in some cases extremely high pressure such as Ice VII and Ice VIII. Using the phase diagram, give the approximate P and T conditions at the triple point for Ice III, Ice V, and liquid water. Determine the approximate temperature and pressure for the triple point for Ices VI, VII, and VIII. What is anomalously different about the fusion curves for Ice VI and Ice VII compared to that of Ice I? What phases exist at 8 kbar and 20 °C? At a constant temperature of −10 °C, start at 3 kbar and increase the pressure to 7 kbar. Identify all the phase changes that occur sequentially as these conditions change. Explain why there is no triple point for the combination of Ice VII, Ice VIII, and liquid water.

Arrange the following substances in order of increasing melting point.

8.87 Use the vapor pressure curves illustrated here to answer the questions that follow. (a) What is the vapor pressure of ethanol (C2H5OH) at 60°C? (b) Considering only carbon disulfide (CS2) and ethanol, which has the stranger intermolecular forces in the liquid state? (c) At what temperature does heptane (C7H16) have a vapor pressure of 500 mm Hg? (d) What are the approximate normal boiling pains of each of the three substances? (e) At a pressure of 400 mm Hg and a temperature of 70°C, is each substance a liquid, a gas, or a mixture of liquid and gas?