CK-12-Chemistry Intermediate

http://www.ck12.org Chapter 16. Solutions

a. vapor pressure

b. freezing point

c. boiling point

2. Explain why the colligative properties of a solvent are affected more by the dissolving of an electrolyte
   compared to an equal amount of a nonelectrolyte.


3. Are the values of Kfand Kbdependent on the identity of the solvent, the solute, or both? Explain.

Problems

4. Find the freezing and boiling point of a 0.760maqueous solution of a nonelectrolyte.


5. Calculate the freezing and boiling point of a solution prepared by dissolving 54.2 g of the nonelectrolyte urea,
   CO(NH 2 ) 2 , in 455 g of water.


6. An aqueous solution of a nonelectrolyte boils at 100.82°C. What is the molality of this solution?


7. A solution is prepared by dissolving 114 grams of NaCl in 475 grams of water. Find the freezing and boiling
   points of this solution.


8. A solution of KBr is observed to freeze at−3.35°C. What would be the freezing temperature of an equal
   molality solution of K 3 PO 4? Explain.


9. How many grams of CaCl 2 should be added to 1.60 kg of water in order to prepare a solution that boils at
   102.58°C?


10. Arrange the following in order from the highest freezing point to the lowest. All solutions are aqueous.
    a. 0.35mZn(NO 3 ) 2
    b. pure water
    c. 0.30mAl 2 (SO 4 ) 3
    d. 0.60mCsCl
    e. 0.85mC 6 H 12 O 6


11. A certain aqueous solution is observed to boil at 104.14°C. What is the freezing point of this solution?


12. Calculate the molar mass of a nonelectrolyte solute if dissolving 4.87 g of it in 80.0 g of water results in a
    solution that freezes at−2.96°C.

Further Reading / Supplemental Links

• ColligativeProperties, (http://www.kentchemistry.com/links/Math/colligativeprop.htm


• BoilingPointElevationandFreezingPointDepressionCalculations, (http://www.kentchemistry.com/links/Math/BPFP.htm

Points to Consider

Many chemical reactions take place in aqueous solutions, and many of those reactions involve electrolytes that
dissociate in solution.

• Which types of reactions most often involve ionic substances?


• How can reactions between ionic substances be shown most succinctly?