SOLVED

 13.1 Multiple Choice Questions 1) Define triple point. A) The temperature, pressure, and density for a gas. B) The temperature at which the boiling point equals the melting point. C) The temperature and pressure where liquid, solid, and gas are equally stable and are in equilibrium. D) The temperature that is unique for a substance. E) The temperature at which the solid and liquid co-exist. 2) Consider the phase diagram shown. Choose the statement below that is true. A) The triple point of this substance occurs at a temperature of 31°C. B) At 10 atm of pressure, there is no temperature where the liquid phase of this substance would exist. C) The solid phase of this substance is higher in density than the liquid phase. D) The line separating the solid and liquid phases represents the ΔHvap. E) None of the above are true. 3) Consider the phase diagram shown. What is the triple point? A) 72.9 atm, 31 °C B) 5.1 atm, -56.7 °C C) 1 atm, -78.5 °C D) 5.1 atm, 31 °C E) 72.9 atm, -56.7 °C 4) Consider the phase diagram shown. What is the normal boiling point? A) 31°C B) -56.7 °C C) -78.5 °C D) 0°C E) 100°C 5) Consider the phase diagram shown. What is the normal freezing point? A) 31°C B) -56.7 °C C) -78.5 °C D) 0°C E) 100°C 6) Consider the phase diagram below. If the dashed line at 1 atm of pressure is followed from 100 to 500°C, what phase changes will occur (in order of increasing temperature)? A) condensation, followed by vaporization B) sublimation, followed by deposition C) vaporization, followed by deposition D) fusion, followed by vaporization E) No phase change will occur under the conditions specified. 7) When an X-ray beam with a wavelength of 180 pm strikes the surface of a crystal, it produces a maximum reflection at an angle of 54.0°. If n=1, what is the separation between layers of atoms in the crystal? A) 151 nm B) 38.9 mm C) 111 nm D) 55.3 nm E) 83.5 nm 8) When an X-ray beam with a wavelength of 120 pm strikes the surface of a crystal with a lattice spacing of 165 nm, what is the maximum reflection angle with a value of n=1? A) 54.0° B) 21.3° C) 32.6° D) 18.4° E) 38.3° 9) When an X-ray beam strikes the surface of a crystal with a lattice spacing of 145 nm, it produces a maximum reflection at an angle of 41.0°. What is the wavelength of the X-ray with a value of n=1? A) 130° B) 164° C) 158° D) 190° E) 167° 10) Determine the radius of an Al atom (in pm) if the density of aluminum is 2.71 g/cm3. Aluminum crystallizes in a face centered cubic structure with an edge length of 2 r. A) 143 pm B) 227 pm C) 96 pm D) 172 pm E) 193 pm 1