BSC 2010 0M04 Quiz (Chapter 3) *Disclaimer: I have made these problems to the best of my ability. However, this is only an overview. Not all information/answers are guaranteed to be accurate, and this information may or may not apply to your class exam. J 1. Label the following diagram with the solute, solution, and solvent. A C B (A) represents the solute which is the substance being dissolved. (B) represents the solvent, which is usually water in an aqueous solution. (C) is the solution which is the homogenous mixture between the solute and solvent. 2. T or F. Hydrogen bonding is the acting bonding force in both cohesion and adhesion. True, cohesion is the attraction between multiple water molecules, whereas adhesion is the attraction between unlike molecules such as water and the edges of a test tube. 3. Ice is ______ than water because the hydrogen bonds are ______ in ice than in water. a. Less dense, less ordered b. More dense, more ordered c. Less dense, more ordered d. More dense, less ordered 4. Water molecules in ice are ____ than water molecules in liquid water. a. More spread out b. Less spread out 5. Which of the following properties of water allows for the regulation of coastal temperatures? a. specific heat b. adhesion c. surface tension d. both a and b Unlike many liquids, water has a very high specific heat. Specific heat is the amount of energy required to change the temperature by 1º C. So, large bodies of water such as the ocean have the ability to regulate the temperature of the surrounding area, preventing drastic changes. 6. Which of the following properties of water explains why our body cools as we sweat? a. Specific heat b. Cohesion c. Evaporative cooling d. Surface tension Evaporative cooling: As liquid evaporates, it gets cooler because the “hottest” molecules are the ones with the highest kinetic energy, and will escape first, leaving “cooler” ones behind. 7. Which of the following explains why water, a polar molecule, is able to climb up a polar plant vessel against gravity? a. Adhesion b. Specific heat c. Cohesion d. Both a and c 8. T or F. Adhesion can explain the property of water known as surface tension, which allows small insects to essentially “walk on water.” This should be cohesion. 9. Why does an aqueous solution dissociate into hydronium and hydroxide ions? Hydrogen bonds are very weak in liquid water, so the water molecules are constantly breaking and reforming. 10. Which of the following would you predict to dissolve best in water? a. CO2 b. H2 c. NaCl d. Xe 11. Which of the following is most hydrophilic? a. CH3OH b. CH4 c. CO2 d. Fats and Oils 12. What does pH measure? a. H+ concentration b. OH-­‐ concentration c. The amount of energy in a solution d. H2O concentration 13. What does temperature measure? a. The intensity of heat b. The average kinetic energy c. The total amount of kinetic energy d. None of the above 14. Which of the following best describes heat? a. The total amount of kinetic energy b. An average of kinetic energy c. The total amount of potential energy d. Volume dependent e. a and d 15. A swimming pool full of water and a coffee pot full of water are both brought to 70º F. How would you compare the heat of the two? a. The swimming pool would have a greater amount of heat. b. The coffee pot would have the greater amount of heat c. They would have an equal amount of heat energy. 16. Using #15, how would you compare the temperature of the two volumes? a. They would have the same temperature. b. They would have differing temperatures. c. It is impossible to know. 17. OH-­‐ is a ______ molecule and H+ is a _______ molecule. a. Hydronium, hydroxide b. Hydroxide, hydronium 18. Which of the following is an acid? a. [H+] = 1 x 10-­‐14 b. [H+] = 1 x 10-­‐7 c. [H+] = 1 x 10-­‐9 d. [H+] = 1 x 10-­‐6 19. Which of the following represents the hydroxide ion concentration of pure water? a. [OH-­‐] = 1 x 10-­‐3 b. [OH-­‐] = 1 x 10-­‐14 c. [OH-­‐] = 1 x 10-­‐4 d. [OH-­‐] = 1 x 10-­‐7 20. How many times greater is the [H+] concentration of a solution of pH 7 than that of pH 11? a. 10 times greater b. 100 times greater c. 1000 times greater d. 10000 times greater 21. Which of the following has the greatest hydroxide ion concentration? a. [H+] = 1 x 10-­‐11 b. pH = 7 c. [OH-­‐] = 1 x 10-­‐13 d. pH = 3