er to the following phase diagram (not to scale!) for ammonia: 111.5 1.00 atm 0.059 195.3 195,4 239.8 405.5 T Kolvin A sample of ammonia at a pressure of 1.00 atm and a temperature of 197 K is heated at constant pressure to a temperature of Choose all that apply O No phase change will occur. O The sample is initially a liquid. O The final state of the substance is a liquid. O The gas initially present will solidify. O The sample is initially a solid.

8.48 Why must the vapor pressure of a substance be measured only after dynamic equilibrium is established?

Referring to Figure 9.7, state what phase(s) is/are present at (a) 1 atm, 100C. (b) 0.5 atm, 100C.(c) 0.8 atm. 50C.

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?

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 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.

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.