1. Section 2 – pg 262 Concentration and Solubility
Chapter 7
Section 2 – pg 262
Concentration and Solubility

2. Pg 262
Concentration
43 gallons of maple sap -> 1 gallon of maple syrup
They change the concentration of the solute in the solvent by evaporating the water leaving a sweeter solution
Fun fact: maple syrup is yummy

3. Changing Concentration
Pg 263
Changing Concentration
Concentrated Solution: a lot of solute dissolved in a certain amount of solvent
Dilute Solution: only a little solute dissolved in a certain amount of solvent

4. Measuring Concentration
Pg 263
Measuring Concentration
To measure concentration, you compare the amount of solute to the total amount of solution
Sunny D – 568 grams of real juice % Concentration grams of SunnyD

5. Pg 263
Solubility
Solubility: a measure of how much solute can dissolve in a solvent at a given temperature
Unsaturated Solution: when you can dissolve more solute
Saturated Solution: when you cannot dissolve more solute

6. Working with Solubility
Pg 264
Working with Solubility
The solubility of a substance tells you how much solute you can dissolve before a solution becomes saturated

7. Pg 264
Using Solubility
You can identify a substance by its solubility b/c it is a characteristic property of matter

8. Factors Affecting Solubility
Pg 264
Factors Affecting Solubility
Factors that affect the solubility of a substance include pressure, the type of solvent, and temperature

9. Pg 265
Pressure
Increasing the pressure increases the solubility of gases
Soda is carbonated due to carbon dioxide being added under pressure

10. Solvents Pg 265 Some solvents and solutes are not compatible
Polar compounds and nonpolar compounds do not mix very well (like oil and water)

11. Pg 265
Solvents
For liquid solutions, the solvent affects how well a solute dissolves (like dissolves like)
Ionic and polar compounds usually dissolve in polar solvents
You can use water and soap to dissolve water-based paints
Nonpolar compounds usually dissolve in nonpolar solvents
Oil based paints require a nonpolar solvent, like turpentine

12. Pg 266
Temperature
For most solids, solubility increases as the temp. increases
This is how we can make rock candy
Unlike most solids, gases become less soluble in a liquid when the temp. of the liquid goes up
Warm soda tastes “flat” b/c less carbon dioxide is able to stay dissolved at the warmer temp.

13. Supersaturated Solution
Pg 267
Supersaturated Solution
Supersaturated Solution has more dissolved solute than is predicted by its solubility at the given temp.
When you drop a crystal of solute into a supersaturated solution, the extra solute will come out of the solution

14. Chapter 7 Section 2 Homework – pg 267

15. 1A. What is concentration?

16. 1B. What quantities are compared when the concentration of a solution is measured?

17. 1C. Solution A contains 50g of sugar. Solution B contains 100g of sugar. Can you tell which solution has a higher sugar concentration? Explain.

18. 2A. What is solubility?

19. 2B. How can solubility help you identify a substance?

20. 2C. Look back at the table in Fig. 7
2C. Look back at the table in Fig. 7. At 0oC, about how many times more soluble in water is sugar than salt?

21. 3A. What are three factors that affect solubility?

22. 3B. How does temp. affect the solubility of most solids?

23. 3C. When you heat water and add sugar, all of the sugar dissolves
3C. When you heat water and add sugar, all of the sugar dissolves. When you cool the solution, some sugar comes out of the solution. Explain why this happens.