This document provides instructions and information for a chemistry class. Students are told to take their seats and get out their homework and launch paper. Yesterday's exit slip data is provided, showing a 90% success rate. Today's objective is to learn how to calculate the concentration of a solution in parts per million (ppm). Examples are then provided for calculating ppm concentrations in solutions containing various amounts of solute and solvent. Key concepts around solutes, solvents, and concentration calculations are reviewed. Students are then instructed to work on practice concentration calculation problems by picking a question card and solving it.

1. Launch: 1/14
 Grab your binder and immediately take a seat!
 Place launch paper and HW (Tuesday’s 1/12 practice
questions) on your desk.
 Yesterday’s Exit Slip Data:
91%
 Today’s Objective: I can calculate the concentration of a
solution in terms of parts per million (ppm).

2. Launch: 1/14
 Grab your binder and immediately take a seat!
 Place launch paper and HW (Tuesday’s 1/12 practice
questions) on your desk.
 Yesterday’s Exit Slip Data:
87%
 Today’s Objective: I can calculate the concentration of a
solution in terms of parts per million (ppm).

3. Launch: 1/14
 Grab your binder and immediately take a seat!
 Place launch paper and HW (Tuesday’s 1/12 practice
questions) on your desk.
 Yesterday’s Exit Slip Data:
90%
 Today’s Objective: I can calculate the concentration of a
solution in terms of parts per million (ppm).

4. Launch: 1/14
 Grab your binder and immediately take a seat!
 Place launch paper and HW (Tuesday’s 1/12 practice
questions) on your desk.
 Yesterday’s Exit Slip Data:
90%
 Today’s Objective: I can calculate the concentration of a
solution in terms of parts per million (ppm).

5. Launch 1/14
1. Concentration is
a. a way to describe the motion of solvent particles in a
solution.
b. a measure of how quickly a solute dissolves.
c. a number that can be measured in g/L or mol/L.
d. how well a solute dissolves in a given amount of solvent.

6. Launch 1/14
3. If 18 mol of NaCl is dissolved in 9L of water, what
is the molarity of the solution in mol/L?
a. .5 mol/L
b. 2 mol/L
c. 3 mol/L
d. 162 mol/L

7. Launch 1/14
4. What is the molarity of a solution that has 20
moles of HNO3 dissolved into 5L of water.
a. 2 M
b. 4 M
c. 20 M
d. 100 M

8. Launch 1/14
5. How many moles of NaOH are needed to make
10L of a 5M solution?
a. .5 mol
b. 2 mol
c. 25 mol
d. 50 mol

9. Announcements
 The semester ends next Friday
 Quiz tomorrow – 25 questions
 Take home notes/practice questions and study hard!
 Look at exit slips online!
 Quiz next Friday

10. January Calendar

11. What is concentration? –
Part III
Mr. Heffner
1/14/10

12. What is concentration?
 Concentration is…
 the amount of solute dissolved a in solution.
 Concentration is measured in…
1. grams per liter (g/L)
2. moles per liter (mol/L)

13. What is concentration?
 Concentration is also measured in…
3. parts per million (ppm)
 the # of solute particles dissolved in 1,000,000 solvent particles
# solute particles
1,000,000 solvent particles

14. Examples
1. A solution of salt water contains 15 grams of salt per
1,000 grams of water. What is the concentration in parts
per million (ppm)?
15 ?
1000 = 1000000
15 15000
1000 = 1000000
15,000ppm

15. Examples
2. A solution of sugar water contains 300 grams of sugar
per 10,000 grams of water. What is the concentration in
parts per million (ppm)?
300 ?
10000 = 1000000
300 30000
10000 = 1000000
30,000ppm

16. Examples
3. What is the concentration in parts per million (ppm) of a
solution of salt water that contains 2 grams of salt per
100,000 grams of water?
2 ?
100000 = 1000000
2 20
100000 = 1000000
20ppm

17. Examples
4. A solution of salt water contains 395 grams of salt per
1000 grams of water. What is the concentration in parts
per million (ppm)?
395 ?
1000 = 1000000
395 395000
1000 = 1000000
395,000ppm

18. Review: Solutes vs. Solvent
 A solution is a homogeneous mixture
 Solute = is dissolved, a solid (or gas), doesn’t move
 Ex: salt
 Solvent = does the dissolving, a liquid, moves randomly
 Ex: water (polar solvent)

19. Review: How are solutes dissolved?
 In a solution…
1. The solute (solid) is attacked by the solvent (liquid)
2. Solid-solid attractions are overpowered by the liquid
3. The solute is surrounded = dissolved

20. Review: What is solubility?
 Factors that affect solubility of solids
1. Temperature: temperature = solubility
2. Surface Area: surface area = solubility
more SA less SA
 Factors that affect solubility of gases
1. Temperature: temperature = solubility
2. Pressure: pressure = solubility

21. Review: Concentration Calculations
 If the question asks for:
 g/L or mol/L or molarity  divide
 grams or moles  multiply
 ppm  ratio
 M = molarity = mol/L

22. Solutions Rotations
 Directions:
 Pick a question and write it down
 Solve showing all work
 When finished, Mr. Heffner will come around to stamp
your work
 Rules:
 If you pick it, solve it
 Only one card at a time
 Show your work!
 Work together

23. Homework
 Study for the quiz!