1. 1 Chapter 5 Chemical Quantities and Reactions 5.1 The Mole Copyright © 2009 by Pearson Education, Inc.

2. 2 Collection Terms A collection term states a specific number of items. 1 dozen donuts = 12 donuts 1 ream of paper = 500 sheets 1 case = 24 cans Copyright © 2009 by Pearson Education, Inc.

3. 3 A mole is a collection that contains the same number of particles as there are carbon atoms in 12.0 g of carbon. 6.02 x 10 23 atoms of an element (Avogadro’s number). 1 mole element Number of Atoms 1 mole C = 6.02 x 10 23 C atoms 1 mole Na = 6.02 x 10 23 Na atoms 1 mole Au= 6.02 x 10 23 Au atoms A Mole of Atoms

4. 4 A mole of a covalent compound has Avogadro’s number of molecules. 1 mole CO 2 = 6.02 x 10 23 CO 2 molecules 1 mole H 2 O = 6.02 x 10 23 H 2 O molecules of an ionic compound contains Avogadro’s number of formula units. 1 mole NaCl = 6.02 x 10 23 NaCl formula units 1 mole K 2 SO 4 = 6.02 x 10 23 K 2 SO 4 formula units A Mole of a Compound

5. 5 Samples of 1 Mole Quantities 1 mole of C atoms= 6.02 x 10 23 C atoms 1 mole of Al atoms= 6.02 x 10 23 Al atoms 1 mole of S atoms= 6.02 x 10 23 S atoms 1 mole of H 2 O molecules= 6.02 x 10 23 H 2 O molecules 1 mole of CCl 4 molecules = 6.02 x 10 23 CCl 4 molecules

6. 6 Avogadro’s number, 6.02 x 10 23, can be written as an equality and two conversion factors. Equality: 1 mole = 6.02 x 10 23 particles Conversion Factors: 6.02 x 10 23 particles and 1 mole 1 mole6.02 x 10 23 particles Avogadro’s Number

7. Using Avogadro’s Number Avogadro’s number is used to o convert moles to particles o convert particles to moles 7 Copyright © 2009 by Pearson Education, Inc.

8. 8 Converting Moles to Particles Avogadro’s number is used to convert moles of a substance to particles. How many Cu atoms are in 0.50 mole of Cu? 0.50 mole Cu x 6.02 x 10 23 Cu atoms 1 mole Cu = 3.0 x 10 23 Cu atoms Copyright © 2009 by Pearson Education, Inc.

9. 9 Converting Particles to Moles Avogadro’s number is used to convert particles of a substance to moles. How many moles of CO 2 are in 2.50 x 10 24 molecules CO 2 ? 2.50 x 10 24 molecules CO 2 x 1 mole CO 2 6.02 x 10 23 molecules CO 2 = 4.15 moles of CO 2

10. 10 1. The number of atoms in 2.0 mole of Al atoms is A. 2.0 Al atoms. B. 3.0 x 10 23 Al atoms. C. 1.2 x 10 24 Al atoms. 2. The number of moles of S in 1.8 x 10 24 atoms of S is A. 1.0 mole of S atoms. B. 3.0 moles of S atoms. C. 1.1 x 10 48 moles of S atoms. Learning Check

11. 12 Subscripts and Moles The subscripts in a formula show the relationship of atoms in the formula. the moles of each element in 1 mole of compound. Glucose C 6 H 12 O 6 In 1 molecule: 6 atoms C 12 atoms H6 atoms O In 1 mole: 6 moles C 12 moles H 6 moles O

12. 13 Subscripts State Atoms and Moles 9 moles of C 8 moles of H 4 moles of O

13. 14 Factors from Subscripts The subscripts are used to write conversion factors for moles of each element in 1 mole of a compound. For aspirin, C 9 H 8 O 4, the possible conversion factors are: 9 moles C 8 moles H 4 moles O 1 mole C 9 H 8 O 4 1 mole C 9 H 8 O 4 1 mole C 9 H 8 O 4 and 1 mole C 9 H 8 O 4 1 mole C 9 H 8 O 4 1 mole C 9 H 8 O 4 9 moles C 8 moles H 4 moles O

14. 15 Learning Check A. How many moles of O are in 0.150 mole of aspirin, C 9 H 8 O 4 ? B. How many atoms of O are in 0.150 mole of aspirin, C 9 H 8 O 4 ?

15. 15 Chapter 5 Chemical Quantities and Reactions 5.2 Molar Mass Copyright © 2009 by Pearson Education, Inc.

16. 16 Molar Mass The molar mass is the mass of 1 mole of an element or compound. is the atomic or molecular mass expressed in grams. Copyright © 2009 by Pearson Education, Inc.

17. 17 Molar Mass from Periodic Table Molar mass is the atomic mass expressed in grams. 1 mole of Ag 1 mole of C 1 mole of S = 107.9 g = 12.01 g = 32.07 g Copyright © 2009 by Pearson Education, Inc.

18. 18 Give the molar mass for each (to the tenths decimal place). A. 1 mole of K atoms =________ B. 1 mole of Sn atoms =________ Learning Check

19. Guide to Calculation Molar Mass of a Compound 19

20. 20 Molar Mass of a Compound The molar mass of a compound is the sum of the molar masses of the elements in the formula. Example: Calculate the molar mass of CaCl 2. ElementNumber of Moles Atomic MassTotal Mass Ca140.1 g/mole 40.1 g Cl235.5 g/mole 71.0 g CaCl 2 111.1 g

21. 21 Molar Mass of K 3 PO 4 Calculate the molar mass of K 3 PO 4. ElementNumber of Moles Atomic MassTotal Mass in K 3 PO 4 K339.1 g/mole 117.3 g P131.0 g/mole 31.0 g O416.0 g/mole 64.0 g K 3 PO 4 212.3 g

22. 22 Some 1-mole Quantities 32.1 g 55.9 g 58.5 g 294.2 g 342.2 g One-Mole Quantities Copyright © 2009 by Pearson Education, Inc.

23. 23 What is the molar mass of each of the following? A. K 2 O B. Al(OH) 3 Learning Check

24. 24 Prozac, C 17 H 18 F 3 NO, is an antidepressant that inhibits the uptake of serotonin by the brain. What is the molar mass of Prozac? 1) 40.1 g/mole 2) 262 g/mole 3) 309 g/mole Learning Check

25. 25 Molar mass conversion factors are fractions (ratios) written from the molar mass. relate grams and moles of an element or compound. for methane, CH 4, used in gas stoves and gas heaters is 1 mole of CH 4 = 16.0 g (molar mass equality) Conversion factors: 16.0 g CH 4 and 1 mole CH 4 1 mole CH 4 16.0 g CH 4 Molar Mass Factors

26. 26 Acetic acid, C 2 H 4 O 2, gives the sour taste to vinegar. Write two molar mass conversion factors for acetic acid. Learning Check Copyright © 2009 by Pearson Education, Inc.

27. 27 Molar mass factors are used to convert between the grams of a substance and the number of moles. Calculations Using Molar Mass Grams Molar mass factor Moles

28. 28 Aluminum is often used to build lightweight bicycle frames. How many grams of Al are in 3.00 mole of Al? Molar mass equality: 1 mole of Al = 27.0 g of Al Setup with molar mass as a factor: 3.00 mole Al x 27.0 g Al = 81.0 g of Al 1 mole Al molar mass factor for Al Moles to Grams

29. 29 Learning Check Allyl sulfide, C 6 H 10 S, is a compound that has the odor of garlic. How many moles of C 6 H 10 S are in 225 g? Copyright © 2009 by Pearson Education, Inc.

30. 30 Grams, Moles, and Particles A molar mass factor and Avogadro’s number convert…

31. 31 Learning Check How many H 2 O molecules are in 24.0 g of H 2 O? 1) 4.52 x 10 23 H 2 O molecules 2) 1.44 x 10 25 H 2 O molecules 3) 8.03 x 10 23 H 2 O molecules

32. 32 Learning Check If the odor of C 6 H 10 S can be detected from 2 x 10 -13 g in 1 liter of air, how many molecules of C 6 H 10 S are present?

33. 33 Chapter 5 Chemical Quantities and Reactions 5.3 Chemical Changes Copyright © 2009 by Pearson Education, Inc.

34. 34 Physical Change In a physical change, the state, shape, or size of the material changes. the identity and composition of the substance do not change. Copyright © 2009 by Pearson Education, Inc.

35. 35 Chemical Change In a chemical change, reacting substances form new substances with different compositions and properties. a chemical reaction takes place. Copyright © 2009 by Pearson Education, Inc.

36. 36 Some Examples of Chemical and Physical Changes Copyright © 2009 by Pearson Education, Inc.

37. 37 Classify each of the following as a 1) physical change or 2) chemical change. A. ____Burning a candle. B. ____Ice melting on the street. C. ____Toasting a marshmallow. D. ____Cutting a pizza. E. ____Polishing a silver bowl. Learning Check

38. 38 Chemical Reaction In a chemical reaction a chemical change produces one or more new substances. there is a change in the composition of one or more substances. Copyright © 2009 by Pearson Education, Inc.

39. 39 Chemical Reaction In a chemical reaction old bonds are broken and new bonds are formed. atoms in the reactants are rearranged to form one or more different substances.

40. 40 Chemical Reaction In a chemical reaction the reactants are Fe and O 2. the new product Fe 2 O 3 is called rust. Copyright © 2009 by Pearson Education, Inc.