1. Mole

2. Objectives: Define mole. Convert mole to number of particles.

3. Mole unit used to express amount of substance based on a certain number of particles

4. Dozen and Mole 1 dozen = 12 pieces 1/2 dozen of apples = 6 apples 2 dozens of eggs = 24 eggs 1 mole = 6.02 x 10 23 particles ½ mole of C atoms = 3.01 x 10 23 C atoms 2 moles of H 2 O molecules = 1.20 x 10 24 H 2 O molecules

5. Mole amount of substance containing the same number of particles as 12 g of C-12. 1 mole contains 6.02 x 10 23 particles (Avogadro’s number) Particles – may be atoms, molecules, ions

6. Check for Understanding 1. How many atoms are there in 1.0 mole sample of Fe? 2. How many molecules are there in 2.5 moles of CO 2 ?

7. Mole and Number of Particles 1 mole of any substance contains 6.02 x 10 23 particles (atoms, molecules, ions) 1 mole C-12 6.02 x 10 23 atoms 1 mole CO 2 6.02 x 10 23 molecules

8. Mole – Number of Particles Conversion MoleNumber of Particles x 6.02 x 10 23 particles/mole Sample Problem 1: How many molecules are there in 0.25 moles of H 2 O? 0.25 mol H 2 O x 6.02 x 10 23 molecules H 2 O mol = 1.505 x 10 23 molecules H 2 O

9. Mole – Number of Particles Conversion MoleNumber of Particles Sample Problem 2: How many moles are there in 1.2 x 10 24 molecules of H 2 O? 1.2 x 10 24 molecules H 2 O x 1 mole H 2 O 6.02 x 10 23 molecules H 2 O = 2.0 moles H 2 O / 6.02 x 10 23 particles/mole

10. Do the following conversions: 1) 1.8 x 10 24 molecules NH 3 = _____ moles 2) 0.75 moles Cl 2 = _____ molecules 3) 3.0 moles Fe = _____ atoms 4) 3.01 x 10 23 ions of NO 3 - = _____ moles

11. Closure: Think-Pair-Share How many molecules are there in 3.0 moles of CO 2 ? 1. Think about how you will go about answering this question. 2. With your group mates, figure out the answer to the question. 3. Make sure everyone in the group knows how to find the answer. 4. If your group is chosen and is able to show the class how to find the correct answer, you earn 3 extra credit points.

12. Check for Understanding 1. How many atoms are there in 1.0 mole sample of Fe? 2. How many molecules are there in 2.5 moles of CO 2 ? 3. What is 1.806 x 10 24 atoms of Cu in number of moles?

13. Molar Mass 1 mole C-12 6.02 x 10 23 atoms 12 g 1 mole CO 2 6.02 x 10 23 molecules 44 g

14. Molar Mass Molar mass – mass of 1 mole of a substance (in grams) - equals the total mass of all the atoms in a substance What is the molar mass of H 2 O? H O 2 moles1 mole 2 (1g) = 2g 1(16g) = 16g 2g+ 16 g = 18 g The molar mass of H 2 O is 18g.

15. Molar Mass What is the molar mass of Mg(OH) 2 ? Mg H O 1 mole2 moles2 moles 1(24g) = 24 g2 (1g) = 2g2 (16g) = 32g 24g+ 2 g +32 g = 58 g The molar mass of Mg(OH) 2 is 58g.

16. Check for Understanding What is the molar mass of: 1. NH 3 2. Cl 2 3. Cu 4. KNO 3 5. Mg 3 (PO 4 ) 2

17. Closure: Write-Pair-Share 1.In your own words, describe how the molar mass of a substance is calculated. 2. Share your answer with your group mates. 3. Make sure that everyone in the group has the correct answer to the question. 4. If your group is chosen and is able to give the correct answer, you earn 2 extra credit point.

18. Objective: Do mass-mole conversions.

19. Mole –Mass Conversion MassMole / Molar Mass x Molar Mass Sample Problem 1 : What is the mass of 0.25 moles of H 2 O? Mass of H 2 O = 0.25 mol x 18 g mol = 4.5 g

20. Mole –Mass Conversion MassMole / Molar Mass x Molar Mass Sample Problem 2. How many moles are there in 36 g of H 2 O? Moles of H 2 O = 36 gx 1 mol 18g = 2.0 mol

21. Do the following conversions: 1) 25 g NH 3 = _____ moles 2) 0.75 g Cl 2 = _____ moles 3) 3.0 moles Fe = _____ grams 4) 4.5 moles KNO 3 = _____ grams Check for Understanding

22. Closure: Write-Pair-Share 1.In your own words, describe how you can do mass to mole and mole to mass conversions. 2. Share your answer with your group mates. 3. Make sure that everyone in the group has the correct answer to the question. 4. If your group is chosen and is able to give the correct answer, you earn 3 extra credit points.

23. Vocabulary Review 1. Solution 2. Solute 3. Solvent 4. Dilute 5. Concentrated

24. Objectives 1. Define molarity. 2. Solve molarity problems. 3. Prepare a solution of a given molar concentration.

25. Molarity - unit of solution concentration - equal to number of moles of solute per liter (or dm 3 ) of solution Molarity Mole of solute Liter of solution =

26. Molarity 1. What is the molarity of a 2 L solution that contains 1 mole of solute? Molarity Mole of solute Liter of solution = = 1 mol 2 L = 0.5 mol/L = 0.5 M

27. Molarity 2.) 29g of NaCl is dissolved in enough water to make a 1L solution. What is the molarity of this solution? Molarity Mole of solute Liter of solution = = 29 g 1 L = 0.50 mol/L = 0.50 M X 1 mol 58 g

28. Check for Understanding Solve these problems: 1. What is the molarity of a 3.00 L solution that contains 4.00 moles of solute? 2. If 18.5 g of KCl is dissolved in enough water to produce 0.5 L of solution, what is the molarity of the solution?

29. 3. If 5.00 g of KBr is dissolved in enough water to produce 500.0 mL of solution, what is the molarity of the solution?

30. Molarity 3.) How many grams of NaCl is needed to produce 1.0 L of a 0.75 M solution? Molarity Mole of solute Liter of solution = = Mole of solute 1.0 L = 0.75 mol x 58 g/mol = 43.5 g = 44 g 0.75 M Mole of solute = 0.75 mol/L x 1.0L = 0.75 mol Mass of solute

31. Check for Understanding Solve this problem: 1. How many grams of KCl should be dissolved in water to produce 0.50 L of a 1.0 M solution?

32. Closure: Write-Pair-Share 1.Answer this question alone: How many grams of KI are needed to produce 1 L of 0.25 M KI solution. 2. Share your answer with your group mates. 3. Make sure that everyone in the group has the correct answer to the question. 4. If your group is chosen and is able to give the correct answer, you earn 3 extra credit points.