This preview shows pages 1–3. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Niu (qn269) Homework 2 flowers (53885) 1 This print-out should have 30 questions. Multiple-choice questions may continue on the next column or page find all choices before answering. 001 10.0 points Of the following substances, which one is NOT expected to dissolve in water? 1. KOH 2. HNO 3 3. CH 3 OH 4. C 6 H 14 correct 5. C 3 H 7 OH 6. C 6 H 12 O 6 Explanation: C 6 H 14 is a long hydrocarbon, not typically soluble in water. Everything else has H-bond. 002 10.0 points When we put sugar in water it melts. 1. False correct 2. True Explanation: Sugar dissolves in water and melts when its temperature is raised above its melting point. 003 10.0 points Which of the following is the best explanation of why sugar is not very soluble in gasoline? Note that all of the statements below are true. 1. The disorder of the system would increase if the sugar dissolved in gasoline. 2. There are dipole-dipole interactions be- tween sugar molecules but not between gaso- line molecules. 3. The attractive forces between gasoline molecules are weaker than the forces between gasoline and sugar molecules. 4. Sugar does not ionize in gasoline. 5. There is hydrogen bonding in the sugar crystal, but not between sugar and gasoline. correct Explanation: The sugar molecule has several polar OH groups which are strongly attracted to po- lar water molecules but poorly attracted to nonpolar gasoline (hydrocarbon) molecules. 004 10.0 points Calculate the number of moles of oxygen that will dissolve in 45 L of water at 20 C if the par- tial pressure of oxygen is 0.21 atm. Henrys constant for oxygen is 0.0013 mol L atm . 1. 0.0062 mol 2. 0.012 mol correct 3. 0.0013 mol 4. 0.00027 mol 5. 0.28 mol Explanation: 005 10.0 points Henrys Law would allow one to predict 1. the solubility of a gas in a liquid given the pressure of gas above the solution. correct 2. the new pressure of a gas if only the volume of the vessel containing the gas were changed. 3. the extent of dissociation of solute in solution. 4. the vapor pressure of the solvent above the pure solvent. 5. elevation in boiling point with the addi- tion of a non-volatile solute. Explanation: Niu (qn269) Homework 2 flowers (53885) 2 Henrys law states that the pressure of a gas above the surface of a solution is proportional to the concentration of gas dissolved in the solution. 006 10.0 points The volume of blood in the body of a certain deep-sea diver is about 7 . 5 L. What is the maximum volume of nitrogen measured at 1 atm and 37 C that could dissolve in the divers blood plasma at a particular depth where the pressure is 10 . 8 atm? Blood cells make up about 55% of the blood volume, and the remaining 45 % is the aqueous solution called plasma. Assume Henrys constant for the nitrogen at 37 C (body temperature) is . 00058 mol L atm ....
View Full Document
This note was uploaded on 02/04/2009 for the course CH 53885 taught by Professor Flowers during the Fall '08 term at University of Texas at Austin.
- Fall '08