J. Muench WORKSHEET #13 _______________________ CHEM 161 name 1. For each molecule, list all of the kinds of intermolecular forces each has – use LD for London dispersion, DD for dipole-dipole, and HB for hydrogen bonding. H O H H a. H C C H b. H O C C O H H H H H H H H H c. Cl C C Cl d. H C C C H H H H H H 2. For the above, predict and arrange them in order of lowest boiling point to the highest. 3. Propyl alcohol and Isopropyl alcohol both have a molecular formula of C3H8O. Yet, the boiling-point of Propyl alcohol (97.2oC) is higher than that for Isopropyl alcohol (82.5oC). Propose a reason for this based on the structures below. H H H H H H H C C C O H H C C C H H H H H O H H Propyl alcohol Isopropyl alcohol 4. How much energy must be absorbed to convert 25g of water at 20.oC to steam at 100.oC? The specific heat of water is 4.184 J/goC and the heat of vaporization of water is 2,260 J/g.J. Muench 5. Freon-12, CCl2F2, is used as a refrigerant. Freon-12 has a heat of vaporization of 289 J/g. What mass of Freon-12 must evaporate to freeze 100.g of water initially at 18oC? The heat of fusion of water is 334 J/g and its specific heat is 4.184 J/goC. 6. What is the vapor pressure of water at 37oC? The heat of vaporization of water is 40,700 J/mol. 7. Sketch a generic phase diagram showing where the solid, liquid, and gas phases will be. Also, indicate the location of the triple and critical points. 8. Chromium metal has a body-centered cubic (BCC) type arrangement for its unit cell. If a sample of chromium metal weighing 35.50 g occupied a volume of 4.93 cm3, then what is the edge length of the unit cell?J. Muench 9. Sodium oxide, Na2O, has a density of 2.57 g/cm3 and an edge length for it’s unit cell of 5.43A. How many atoms (Na and O) are in each unit cell of sodium oxide? (Note: solving for the type of cubic unit cell is not the final answer!) 10. For each of the following pairs, based on its type of solid and/or intermolecular forces, predict which will have the higher melting point. a. HF or HCl b. Na or Fe c. C(dia) or C6H6 d. NaF or