1. Week 22 Chemistry Percent Composition, Empirical Formulas, Molecular Formulas

2. Record your Learning Target Warm Up: 3 Minutes Stay in your own seat You should be working SILENTLY A certain bag of M&M’s has 8 blue candies, 7 red candies, 4 green candies, and 6 yellow candies. What percentage of the bag is blue M&M’s? Do the warm up in OneNote

3. Agenda • Warm Up [6 minutes] • Pre-Lab/Expectations [7 minutes] • Bubble Gum Lab[18 minutes] • Answer Key [ 4 minutes] • Modeling Tracking [5 minutes] • You Track [10 minutes] • Closing[3 Minutes]

4. Bubble Gum Lab

5. Problem What percentage of Double Bubble Gum is composed of sugar?

6. Pre-Lab Question According to the nutritional manufacturer, each piece of gum has a mass of 6g with 5g of sugar. Using this information, what percent of the gum is sugar by mass?

7. Lab Expectations • Work in assigned groups • Raise your hand if you have a question • No gum should be left on the desks

8. General information: How to do the lab • Find the mass of your piece of gum before chewing (include the wrapper) • Chew your gum for ~5 minutes • Find the mass of your piece of gum after chewing Gum should be placed in wrapper before putting it on mass balance • Complete analysis and post-lab questions

9. Bubble Gum Lab 15 Minutes You each need One Piece of Gumand your Brain Good Luck!!!

10. Answer KeyAs Mr. Ghosh goes through the answers, highlight the ones you got wrong • A • C • A • D • D • C • A • D • C • B • B 12. B 13. B 14. A 15. C 16. A 17. C 18. A 19. A 20. B 21. C

11. Class Averages (and Top Scores)

12. What does Tracking Look Like?

13. What does Tracking Look Like?

14. What does Tracking Look Like?

15. What does Tracking Look Like?

16. What does Tracking Look Like?

17. Percent Mastery 25% Your points x100 Total points Cathy received 1 point out of 4 possible points. What is her percent mastery?

18. What does Tracking Look Like?

19. Your Turn • Go to shschem.weebly.com (our class website) • Hover over my page: Mr. Ghosh  Homework Assignments  ESL (or regular) Chemistry • Under Homework Assignments, there is a new one labeled “Unit 5 Tracking” • Download (and save) this and fill it out

20. Closing • Explain the purpose of today’s lab

21. Warm Up: 4 Minutes Stay in your own seat You should be working SILENTLY • Log into your computer • Go to m.socrative.com • Enter room number: 230538 • Finish all questions • When you are finished, check your grades on PS Connect

22. Agenda • Warm Up [7 minutes] • Notes/Examples [15 minutes] • Guided Practice [12 minutes] • Independent Practice [15 minutes] • Closing[3 Minutes]

24. What is % Composition?? Percent by mass of each element in a compound

25. What is % Composition??

26. Example 1: A compound contains 2.0g of sodium, 3.5g of oxygen, and 0.5 g of hydrogen. What is the percent composition of this compound?

27. Example 2: What is the percent composition by mass of the elements in the compound, AgNO3?

28. Guided Practice • Teacher: 1. Will show the problem on the board • Students: • Take 24 seconds to identify your given and unknown. • Take 46 seconds to speak with your shoulder partner about the problem • Be ready to share when Mr. Ghosh says SWAG

29. Guided Practice 1: 9.03 g Magnesium combines completely with 3.48 g Nitrogen to form a compound. What is the percent composition of Nitrogen in this compound? 27.82 % N

30. Guided Practice 2: What is the percent composition by mass of the elements in Mercury (II) Oxide? 92.6% Hg 7.4% O

31. Guided Practice 3: What is the percent composition by mass of the elements in K2CO3? 56.6% K 8.7% C 34.7% O

32. Independent Practice Take some time to practice finding the % composition of the following compounds 85% Practice makes Perfect

33. Closing How do you find the percent compositionof an element in a compound?

34. Write the Learning Target Warm Up: 4 Minutes Stay in your own seat You should be working SILENTLY • Log into your computer • Go to m.socrative.com • Enter room number: 230538 • Finish all questions • When you are finished, check your grades on PS Connect

35. Agenda • Warm Up [7 minutes] • Notes/Examples [15 minutes] • Guided Practice [12 minutes] • Independent Practice [15 minutes] • Closing[3 Minutes]

36. Goal For Today Percent Composition: 79.8% C, 20.2% H Student Given: Student Answer: CH3

37. Empirical Formulas empirical formula of glucose = CH2O Shows the lowest number ratio of atoms in a compound

38. Example 1: What is the empirical formula for a chemical compound that is 79.8% C and 20.2% H?

39. How to Compose the Empirical Formula? 79.8% C and 20.2% H Step 1: Convert Percent to Grams Step 2: Convert Grams to Moles by dividing grams by the atomic mass of each element.

40. How to Compose the Empirical Formula? 79.8% C and 20.2% H Step 3:Divide both molar quantities by the smallest mole quantity to determine the subscript for each element in the formula

41. Example 2: What is the empirical formula for a compound that is 81.7% Be and 18.3% H?

42. Guided Practice • Teacher: 1. Will show the problem on the board • Students: • Take 22 seconds to identify the elements involved. • Take 68 seconds to solve the problem with your shoulder partner • Be ready to share when Mr. Ghosh says SWAG

43. Guided Practice 1: What is the Empirical Formula of a compound that is 67.6% Hg, 10.8% S, and 21.6 % O by mass? HgSO4

44. Guided Practice 2: What is the Empirical Formula of a compound that is 88.2 % Oxygen and 11.8% Hydrogen by mass? H2O

45. Guided Practice 3: What is the empirical formula of a compound that is made from 50% Cesium and 50% Iodine by mass? CsI

46. Independent Practice 85% Practice makes Perfect

47. Closing • What is the empirical formula? • How do you compose the empirical formula?

48. Warm Up: 4 Minutes Stay in your own seat You should be working SILENTLY • Log into your computer • Go to m.socrative.com • Enter room number: 230538 • Finish all questions • When you are finished, check your grades on PS Connect

49. Agenda • Warm Up [7 minutes] • Notes/Examples [15 minutes] • Guided Practice [12 minutes] • Independent Practice [15 minutes] • Closing[3 Minutes]

50. More Empirical Formulas!!