Section 9.1 Worksheet - practice questions PDF

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Solutions 1. What causes a solution to form? 2. How does the phrase like dissolves like relate to solutions? 3. Toluene (C6H5CH3) is widely used in industry as a nonpolar solvent. Which substances should dissolve in toluene? a. Water (H2O) b. Sodium sulfate (Na2SO4) c. Octane (C8H18) 4. Would I2 be more soluble in CCl4 or H2O? 5. Define solution. 6. Give several examples of solutions. 7. What is the difference between a solvent and a solute? 8. Can a solution have more than one solute in it? Can you give an example? 9. Does a solution have to be a liquid? Give several examples to support your answer. 10. Give at least two examples of solutions found in the human body. 11. Which substances will probably be soluble in water, a very polar solvent? a. Sodium nitrate (NaNO3) b. Hexane (C6H14) c. Isopropyl alcohol [(CH3)2CHOH)] d. Benzene (C6H6) 12. Which substances will probably be soluble in toluene (C6H5CH3), a nonpolar solvent? a. Sodium nitrate (NaNO3) b. Hexane (C6H14) c. Isopropyl alcohol [(CH3)2CHOH)] d. Benzene (C6H6) 13. The solubility of alcohols in water varies with the length of carbon chain. For example, ethanol (CH 3CH2OH) is soluble in water in any ratio, while only 0.0008 mL of heptane (CH3CH2CH2CH2CH2CH2CH2OH) will dissolve in 100 mL of water. Propose an explanation for this behavior. 14. Dimethyl sulfoxide [(CH3)2SO] is a polar liquid. Based on the information in Exercise 13, which do you think will be more soluble in it—ethanol or heptanol?

ANSWER KEY 1. Solutions form because a solute and a solvent have similar intermolecular interactions. 2. It means that substances with similar intermolecular interactions will dissolve in each other. 3. Octane only 4. I2 is nonpolar. Of the two solvents, CCl4 is nonpolar and H2O is polar, so I2 would be expected to be more soluble in CCl4. 5. A homogeneous mixture 6. Vinegar, dextrose IV, saline IV, coffee, tea, wine

7. A solvent is the majority component of a solution; a solute is the majority component of a solution. 8. Yes, Coke or Pepsi has sugar, caffeine and carbon dioxide as solutes. 9. A solution does not have to be a liquid; air is a gaseous solution, while some alloys are solid solutions (answers will vary) 10. Urine, plasma 11. a. probably soluble b. probably not soluble c. probably soluble d. probably not soluble 12. a. probably not soluble b. probably soluble c. probably not soluble d. probably soluble 13. small alcohol molecules have strong polar intermolecular interactions, so they dissolve in water. In larger alcohol molecules, the nonpolar end overwhelms the polar end, so they do not dissolve very well in water. 14.Ethanol is a smaller molecule. It will be more soluble in water than heptanol...