1. 1 Chemical Quantities or

2. 2 Representative particles n The smallest pieces of a substance. n For an element it is an atom. (Ex: Na) n For a covalent compound it is a molecule. (Ex: CO 2, H 2 ) n For an ionic compound it is a formula unit. (Ex: NaCl)

3. 3 n Mole Video Mole Video Mole Video

4. 4 What is a Mole? What is a Mole? n A unit of counting atoms and molecules. n 1 mole is 6.02 x 10 23 particles. n 6.02 x 10 23 is called Avogadro's number.

5. 5 What is a Mole? n A mole is like a dozen. A dozen is defined as 12. n A dozen eggs = 12 eggs, a dozen pencils = 12 pencils, etc… n A mole is defined as 6.02 x 10 23. n A mole of pencils = 6.02 x 10 23 pencils n A mole of baseballs = 6.02 x 10 23 baseballs

6. 6 What is a Mole? n Avogadro’s number is a very large number! n 602,000,000,000,000,000,000,000 n If there were a mole of rice grains, all the land area in the whole world would be covered with rice to a depth of 75 meters! n A mole of hockey pucks would be equal to the mass of the moon.

7. 7 A Mole is A Lot of Things n Assuming that each human being has 60 trillion body cells (6.0 x 10 13 ) and the Earth’s population is 7.05 billion, the total number of living human body cells on the Earth at the present time is 4.2 x 10 23 or about 2/3 of a mole!

8. 8 A Mole is A Lot of Things n If one mole of pennies were divided up among the Earth’s population, each person would receive 8.54x10 13 pennies. Personal spending at the rate of one million dollars a day would use up each persons wealth in just over 2300 years! Life would not be comfortable. The surface of the Earth would be covered in copper coins to a depth of at least 420 meters!

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10. 10 Mass n 1 atom of sulfur = 32 amu n amu = atomic mass unit n We do not measure mass in amu, we use grams. n 1 mole of sulfur atoms = 32 grams n 1 mole of sulfur atoms = 6.02 x10 23 atoms

11. 11 Mass n 1 atom of Li = n 1 mole of Li atoms = n 1 molecule of H 2 O = n 1 mole of H 2 O molecules = 7 amu 7 grams 6.02 x 10 23 atoms 18 amu 18 grams 6.02 x 10 23 molecules

12. 12 Molar Mass n The mass of 1 mole of a substance (in grams). n What is the molar mass of: 1. Sn 119 grams 119 grams 2. Ba 137 grams 137 grams 3. Oxygen 32 g (O 2 ) 32 g (O 2 )

13. 13 Molar Mass 4. C 12 H 22 O 11 342 g 342 g 5. Fe 2 (SO 4 ) 3 400 g 400 g 6. Ca(C 2 H 3 O 2 ) 2 158 g 158 g

14. 14 Mole Calculations Mole – Mass 1. What is the mass of 2.50 mol of potassium? 2. Convert 0.522 moles of Zn to grams. 3. 145 grams of silver = _____ moles 4. 28.0 g of CO 2 = _____ moles 5. 1.50 moles C 6 H 12 O 6 = ____ grams

15. 15 Mole - Particles 1. Calculate the # of moles contained in 4.70 x 10 24 atoms of calcium. 2. How many molecules of CO 2 are contained in 4.56 moles of CO 2 ? 3. 0.025 mol of Ba = _____ atoms 4. 1.75 x10 23 molecules NH 3 = ____ mol. 5. 1.75 mol NaCl = _____ formula units

16. 16 Mass - Particle 1. How many grams of water are contained in 5.87 x 10 22 molecules? 2. Convert 122 g of NaCl to formula units. 3. 86.0 g of CO 2 = _____ molecules 4. How many atoms of silicon are contained in a 37.9 g sample of silicon?

17. Mole Song

18. 18 What is Avogadro’s favorite movie?

19. Two Ways to Find Molar Mass 1. Use the periodic table Ex: What is the molar mass of C 4 H 10 ? 58 g 2. Using the formula

20. 20 1. Calculate the molar mass of a compound if 0.0392 mol of the compound has a mass of 6.54 g. 2. If 5.22 x10 24 atoms of an unknown element has a mass of 1032 g, what is the element?

21. 21 Chemical Equivalents n Equal moles 1. Calculate the # grams of carbon that are chemically equivalent to 16 g of sulfur. 2. Calculate the # grams of As that are chemically equivalent to 50.0 g of Sr

22. 22 From Compounds to Elements n 1 molecule of C 6 H 12 O 6 contains: 6 atoms of C 6 atoms of C 12 atoms of H 12 atoms of H 6 atoms of O 6 atoms of O n 1 mole of C 6 H 12 O 6 contains: 6 moles of C 6 moles of C 12 moles of H 12 moles of H 6 moles of O 6 moles of O

23. 23 Examples 1. Given 1.25 x10 24 molecules of C 6 H 12 O 6, calculate: A. moles of C 6 H 12 O 6 A. moles of C 6 H 12 O 6 B. grams of C 6 H 12 O 6 B. grams of C 6 H 12 O 6 C. grams of carbon C. grams of carbon D. atoms of oxygen D. atoms of oxygen E. atoms of hydrogen E. atoms of hydrogen

24. 24 Examples 2. Given: 50.0 g of (NH 4 ) 2 Cr 2 O 7. Calculate : A. Number of atoms of oxygen A. Number of atoms of oxygen B. Number of grams of hydrogen. B. Number of grams of hydrogen.

25. 25 Examples 3. How many atoms of carbon are there in 1.23 moles of C 6 H 12 O 6 ?

26. 26 Examples 4. Calculate the length of Al foil needed to have 1.00 mole of Al. The density of Al is 2.70 g/cm 3. The foil is 30.5 cm wide and the height (thickness) is 0.00250 cm.

27. Percent Composition

28. 28 Example 1. Calculate the percent composition of a compound that is 29.0 g of Ag with 4.30 g of S.

29. 29 Examples 2. Calculate the percent composition of C 2 H 4.

30. 30 Examples 3. What is the percent composition of aluminum carbonate?

31. 31 Hydrates 4) Calculate the % of water in MgSO 4 ∙ 7H 2 O

32. 32 Examples 5) Calculate the % of carbon in C 12 H 22 O 11. 6) How many grams of carbon are contained in 75.0 g of C 12 H 22 O 11 ? 7) (Honors) How many grams of C 12 H 22 O 11 are needed to have 50.0 g of carbon?

33. 33 Empirical Formula

34. 34 The Empirical Formula n The lowest whole number ratio of elements in a compound. (Simplest formula)

35. 35 Examples Are the following empirical formulas? 1. N 2 O 4 no no 2. NH 3 yes yes 3. K 2 SO 4 yes yes 4. C 6 H 12 O 6 no no

36. 36 Calculating Empirical Formulas n Assume you have 100 g of the compound. n The % = grams. n Convert grams to moles. n Find lowest whole number ratio by dividing by the smallest moles.

37. 37 Example 1) Calculate the empirical formula of a compound composed of 38.67 % C, 16.22 % H, and 45.11 %N. 1) Calculate the empirical formula of a compound composed of 38.67 % C, 16.22 % H, and 45.11 %N.

38. 38 Example 2) Caffeine is 49.48% C, 5.15% H, 28.87% N and 16.49% O. What is its empirical formula? 2) Caffeine is 49.48% C, 5.15% H, 28.87% N and 16.49% O. What is its empirical formula?

39. 39 Example 3) Calculate the empirical formula of a compound that contains 57.6% Sr, 13.8% P and 28.6% O.

40. 40 Molecular Formula n Real (actual) formula. n Example: C 6 H 12 O 6 molecular formula for glucose n Empirical formula is CH 2 O

41. 41 Example 1) A compound has an empirical formula of ClCH 2 and a molar mass of 98.96 g/mol. What is its molecular formula? 2) A compound has an empirical formula of C 6 H 8 O and a molar mass of 290.0 g/mol. What is its molecular formula?

42. 42 Example 3)Ibuprofen is 75.69 % C, 8.80 % H, 15.51 % O, and has a molar mass of about 206 g/mol. What is its molecular formula?

43. 43 Hydrates n Compounds that contain water n Anhydrous- without water n Ex: MgSO 4 ∙7H 2 O n Magnesium sulfate heptahydrate n This is a common substance called epsom salts

44. 44 Examples 1) Calculate the % of water in : A. SrCl 2 ∙6H 2 O B. ZnSO 4 ∙7H 2 O

45. 45 Examples 2) 3.50 g of Na 2 CO 3 ∙xH 2 O was heated to drive off the water. After heating, 1.30 g of the anhydrous compound remained. Calculate: A. % H 2 O A. % H 2 O B. Formula of the hydrate B. Formula of the hydrate