Name ________________________________ Class _____
Notes – Solutions and Solubility
1. List three factors that affect solubility, the ability of a solute to dissolve readily in a solvent.
(See p. 393) (Heat it, stir it, crush it.)
a. Temperature – More solute dissolves faster in a hot solvent than a cool solvent.
b. Stirring – Solutes dissolve faster when stirred than not stirred.
c. Particle size – Solutes that are small dissolve faster than large solutes.
2. Which will dissolve faster, a sugar cube or granulated sugar? Granulated sugar
3. Which will dissolve faster, sugar in cold water or sugar in warm water? Warm water
4. Which will dissolve faster, a sugar cube that is stirred or one that is not stirred? stirred
5. Temperature affects solubility. Observe the graph below, which shows the solubility of sugar
and salt over a range of temperatures.
How many grams of sugar will dissolve at
20˚C? ___200 g______
How many grams of sugar will dissolve at
70˚C? ____325 g______
How many grams of salt will dissolve at 20˚C?
____about 30 g______
How many grams of salt will dissolve at 80˚C?
____about 40 g______
Name ________________________________ Class _____
6. Graph the following information to show a solubility curve for potassium nitrate, KNO3 . Make
sure that your graph has a title and that the x and y axes are labeled.
Temperature
(x-axis)
10
25
40
55
70
Solubility (grams per 100 mL solvent)
(y-axis)
23
40
60
90
130
Name ________________________________ Class _____
Hey look at this! In chemistry, when we dissolve something in water, it is called a
“solution.” For example, when we add sugar to water and stir until it is all dissolved, it
is called a “sugar solution.”
Notes – Molarity (p.404)
7. What is the symbol for molarity? ___M_____
8. What is the formula to calculate molarity? (look for the blue box on page 404.)
Molarity = mol / liters
9. What is the molarity of a solution that contains 3.4 moles of solute dissolved in enough
water to make 2.0 L of solution?
3.4 / 2.0 = 1.7 M
10. What is the molarity of a solution that contains 1.2 mol of sodium chloride dissolved in
enough water to make 2.1 L of solution?
1.2 / 2.1 = 0.57 M
11. What is the formula for finding the new concentration after a solution is diluted?
(p. 404)
M1V1 = M2V2 (honors only)
12. If a student makes a new solution by diluting 250 mL of 6 M hydrochloric acid to a new
volume of 500 mL, what is the new molarity? Show formula and work.
Use M1V1 = M2V2.
6*.250 = M2 * 0.500
M2 = 3
Name ________________________________ Class _____
Review for water and Solutions Test
1. Draw a water molecule. What is the shape of the water molecule? Where are the
regions of positive and negative charge? What is the overall charge on the water
molecule?
Water is bent. Oxygens are negative, hydrogens are positive. (Look in your notes.)
The overall charge is zero.
2. What type of bond is primarily responsible for the surface tension of water?
Polar covalent bond
3. List three things you can do to make a solid substance dissolve faster in a solution.
Heat it, stir it, crush it
4. Explain the rule “like dissolves like.” Give examples.
Polar solvents dissolve polar and ionic solutes.
Nonpolar solvents dissolve nonpolar solutes.
5. Positive charges are attracted to ___negative___ charges.
6. Know how to read and interpret a solubility graph.
7. How is the solubility of a gas different from the solubility of a solid or a liquid?
Gases are LESS soluble at higher temperatures.
8. Know the vocab.