1. Chapter 7 Solutions
7.1
Solutions

2. Solutions: Solute and Solvent
are homogeneous mixtures of two or more substances
form when there is sufficient attraction between solute and solvent molecules
have two components: the solvent, present in a much larger amount, and the solute, present in a smaller amount

3. Solutes Solutes spread evenly throughout the solution
cannot be separated by filtration
can be separated by evaporation
are not visible, but can give a color to the solution
A solution of copper(II) sulfate (CuSO4) forms as particles of solute dissolve and become evenly dispersed among the solvent (water) molecules.

4. Types of Solutes and Solvents
Solutes and solvents may be solids, liquids, or gases.

5. Water as a Solvent Water is one of the most common solvents in nature
is a polar molecule due to polar O–H bonds
molecules form hydrogen bonds important in many biological compounds

6. Solutions with Ionic and Polar Solutes
NaCl crystals undergo hydration as water molecules surround each ion and pull it into solution.
solid separate ions

7. Solutions with Nonpolar Solutes
Nonpolar solutes require nonpolar solvents to form a solution.

8. “Like Dissolves Like”
“Like dissolves like”: polarity of solute and solvent must be similar to form a solution.

9. Learning Check Identify the solute in each of the following solutions.
A. 2 g of sugar and 100 mL of water
B mL of ethyl alcohol and 30.0 mL of methyl alcohol
C mL of water and 1.50 g of NaCl
D. Air: 200 mL of O2 and 800 mL of N2

10. Solution Identify the solute in each of the following solutions.
A. 2 g of sugar and 100 mL of water
The solute is sugar.
B mL of ethyl alcohol and 30.0 mL of methyl alcohol
The solute is methyl alcohol.
C mL of water and 1.50 g of NaCl
The solute is NaCl.
D. Air: 200 mL of O2 and 800 mL of N2
The solute is O2.

11. Learning Check Solid LiCl is added to water. It dissolves because
A. the Li+ ions are attracted to the
1) oxygen atom ( −) of water
2) hydrogen atom ( +) of water
B. the Cl− ions are attracted to the

12. Solution Solid LiCl is added to water. It dissolves because
A. the Li+ ions are attracted to the
1) oxygen atom (−) of water
B. the Cl− ions are attracted to the
2) hydrogen atom ( +) of water

13. Learning Check
Which of the following solutes will dissolve in water? Why?
A. Na2SO4
B. gasoline (nonpolar)
C. I2
D. HCl

14. Solution Which of the following solutes will dissolve in water? Why?
A. Na2SO4 will dissolve, ionic
B. gasoline (nonpolar) will not dissolve, nonpolar
C. I2 will not dissolve, nonpolar
D. HCl will dissolve, polar
Most polar and ionic solutes dissolve in water because water is a polar solvent. Nonpolar solutes will not dissolve in water.