Chapter Seven: Solutions

1. Define the following terms: a. aqueous solution- a solution in water b. colloid mixture of large molecules that will not settle or join with the other substance it is in c. concentration ratio of mass or volume of solute to mass or volume of solvent d. heterogeneous a mixture is made up by two or more different substance which are (mixed) together but are not combined e. homogenous mixture mixture that is uniform throughout f. Henry’s Law An expression for calculating the solubility of a gas in a fluid based on temperature and partial pressure g. solution mixture of two or more substances h. Molarity concentration measured by the number of moles of solute per liter of solution. i. Osmosis The tendency of molecules of a solvent to pass through a semipermeable membrane from a less concentrated solution into a more concentrated solution j. Solubility the quantity of a particular substance that can dissolve in a particular solvent

2. Classify each substance as a heterogeneous mixture, solution, or colloid. a. Cherry Garcia ice cream ( cherry ice cream + chocolate bits + cherries) colloid b. mayonnaise solution c. seltzer water solution d. nail polish remover e. brass (an alloy of copper and zinc) heterogeneous

3. Which compounds are water soluble? a. sodium nitrate (NaNO3) yes b. methane (CH4) no c. potassium bromide (KBr) yes d. carbon tetrachloride (CCl4) no

4. Which pairs of compounds will form a solution? NEED HELP a. benzene (C6H6) and hexane (C6H14) b. NaCl and hexane (C6H14) c. sodium sulfate (Na2SO4 ) and water (H2O) d. Water (H2O) and xarbon tetrachloride (CCl4)

5. Why does a soft drink become “flat” faster when it is left open at room temperature compared to when it is left open in the refrigerator? molecules move faster the warmer they are

6. Predict the effect each change has on the solubility of (1) Na2CO3 (s) (2) N2(g). a. increasing the temperature more b. increasing the pressure more c. decreasing the temperature less d. decreasing the pressure. less

7. A commercial mouthwash contains 4.3 g of ethanol and 0.021 g of antiseptic in each 30. –mL portion. Calculate the weight/volume percent concentration of each component. 0.14g/ml ethanol and 0.0007g/ml of antiseptic

8. How many ml of ethanol are contained in a 30. –mL portion of a mouthwash that has 8.0% (v/v) of ethanol? 2.4g

9. A cough medicine contains 0.20% (w/v) dextromethorphan, a cough suppressant, and 2.0%m(w/v) guaifenisin, an expectorant. How many milligrams of each drug would you obtain from 3.0 tsp of cough syrup? (1 tsp = 5 mL) NEED HELP

HAVING A HARD TIME WITH THIS PAGE. WOULD LIKE TO COME BY WHEN I COME TO TOWN AND SEE IF YOU CAN SIT WITH ME AND HELP ME TO UNDERSTAND.

10. Calculate the Molarity of each aqueous solution with the given amount of NaCl (molar mass 58.4 g/mol) and final volume. a. 1.0 mol in 0.50 L c. 0.050 mol in 5.0 mL c. 2.0 mol in 250 mL d. 12.0 g in 2.0 L
11. How many milliliters of a 1.5 M glucose solution contain each of the following number of moles? a. 0.15 mol b. 0.020 mol

12. How many grams of NaCl are contained in each of the following volumes of a 1.25 M solution? a. 0.10 L b. 50.0 mL

13. What is the concentration of a solution formed by diluting 25.0 mL of a 3.8 M glucose to 275 mL?

14. Ketamine. An anesthetic, is supplied in a solution of 100. g/mL. If 2.0 mL of this solution is diluted to a volume of 10.0 mL, how much of the diluted solution should be administered to supply a dose of 75 mg?

15. Describe the process that occurs when a 1.0 M NaCl solution is separated from a 1.5 M NaCl solution by a permeable membrane in terms of each of the following: a) the identity of the substances that flows across the membrane b) the direction of flow before and after equilibrium is achieved. c) the height of the solutions after equilibrium is achieved.