1. Which of the following would have the highest vapor pressure (vp) at 25C ? A. Water (boiling point =100C ) C. Octane (boiling point =126C ) B. Acetone (boiling point =56C ) D. They all have the same vp at 25C. 2. Based on the phase diagram shown at right, how will the melting point of this substance change if the pressure is lowered below 1atm ? A. The melting point will increase. B. The melting point will decrease. C. The melting point will remain the same. D. The substance will not melt at pressures above 1atm; instead, the solid sublimes to form the gas phase. E. None of these choices are correct. 3. List ALL IMF's that would occur in a sample containing only the following molecule. A. Dispersion forces B. Dipole-dipole forces C. Hydrogen-bonding forces D. The forces given in (A) and (B). E. The forces given in (A), (B) and (C). 4. Select the pair of substances in which the one with the higher vapor pressure at a given temperature is listed first. A. C7H16,C5H12 C. Xe,Ne B. H2S,H2O D. CH3CH2OH,CH3OCH3 5. What adjective best describes the solid compound iodine pentafluoride (IF5) ? A. network C. atomic B. molecular D. ionic 6. Assuming ideal behavior, which of the following solutions would have the greatest boiling poir A. 0.10mKCl(aq) D. Two of these would have B. 0.15mCH3OH(aq) the greatest (and same) C. 0.15mHNOHN3(aq) boiling point. 7. With increasing temperature, the solubility of most solids and that of gases A. Increases, increases C. Increases, decreases B. Decreases, increases D. Decreases, decreases