1 / 46

CHEMISTRY 11

CHEMISTRY 11. TEACHER’S NOTES. LESSON. FOR THE TEACHER. Lesson Objectives. Review, reinforce, and extend the concepts in Chapter 6: Quantities in Chemical Formulas. This lesson relates to expectations D2.1, D2.3, D2.4, D3.1, D3.2, and D3.3. Lesson Notes. Slide 6

beryla
Download Presentation

CHEMISTRY 11

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CHEMISTRY 11 TEACHER’S NOTES LESSON

  2. FOR THE TEACHER Lesson Objectives • Review, reinforce, and extend the concepts in Chapter 6: Quantities in Chemical Formulas. • This lesson relates to expectations D2.1, D2.3, D2.4, D3.1, D3.2, and D3.3. Lesson Notes • Slide 6 • As a prompt to the first task, ask students to think about the consequences of excess sodium in terms of the given phrases. With the second task, the key point is that the average sodium level is above not only the recommended level, but also the maximum tolerance. • Slides 12 – 15 • This calculation extends the process students followed in slides 9 and 10. They use the compound amount to determine, first, the number of formula units, and then the number of individual ions. Discuss the steps in the whole process with students, in terms of how each step leads logically to the next.

  3. FOR THE TEACHER Lesson Notes • Slide 16 • Suggest to students that more than one thing is changing during the animation. [mass, number of molecules, number of atoms] • Slides 19 and 20 • For slide 20, prompt students to think about which element they will use as the base of the ratio, and why. • Slides 23 • The discussion question encourages students to think about how variables such as the type of paper might affect the outcome of an investigation. • Slides 24 • Prompt the students to think about where they would begin in the sequence, and where they need to end. Also, which steps must logically follow other steps?

  4. Diabetes: Diagnosis and Management Section 6.1 Diabetes is usually diagnosed by tests that reveal excess glucose in a patient’s blood. Diabetes can be managed, often by diet alone, reducing blood glucose back toward normal levels and helping patients lead healthy lives. Match the correct type of analysis to each blood glucose test apparatus. qualitative quantitative

  5. Section 6.1 Discussion: Diabetes: Diagnosis and Management Discuss why a quantitative instrument would be better suited to diabetes management than would a qualitative one.

  6. Sodium Ions: Too much of a Good Thing? Section 6.2 • Complete the following statements using the words or phrases below. water blood pressure fluid levels Sodium ions are needed to help regulate __________ in the body. Excess sodium ions make the body retain __________ which raises __________. 2. Match each quantity of sodium with Health Canada’s description. ● 1500 mg 2300 mg 3400 mg ● average Canadian intake recommended daily intake maximum tolerable limit ● ● ● ●

  7. Section 6.2 Discussion: Sodium: Too Much of a Good Thing? Excess sodium creates health risks for human beings. Why can we not just eliminate sodium from our food?

  8. What’s in a Mole? Section 6.3 Complete each statement by filling in the blank space(s). sucrose • A mole of __________ has a mass of exactly 12 g. • In chemistry, an entity could be an __________, __________, __________, or __________. sodium chloride carbon • When measured, 1-mol samples of sucrose, sodium chloride, and carbon have different __________ and volumes, but the same number of __________, 6.02 × 10. Click the screen for a note: Avogadro’s Constant is 6.02 × 1023.

  9. Calculating Amount from Mass Section 6.4 A portion of French fries contains 1.15 g of sodium chloride, NaCl. Calculate the amount of sodium chloride in 1.15 g. Use the given data to complete the calculation. g g g Given: mNaCl = 1.15 g; Mna = 22.99 ; MCl = 35.45 mol mol mol Required: amount of sodium chloride, nNaCl Solution: Step 1: Calculate to molar mass of sodium chloride, MNaCl. MNaCl = 1(MNa) + 1(MCl) = __________ + __________ MNaCl = __________ Step 2

  10. 1 mol 1 mol g g Calculating Amount from Mass Section 6.4 Step 2: Multiply the mass of sodium chloride by a conversion factor of . nNaCl = g × nNaCl = mol Statement: There are of sodium chloride in a 1.15 g sample.

  11. Section 6.4 Discussion: Calculating Amount from Mass How would your solution method change if you were calculating the amount of calcium chloride in a 1.15 g sample?

  12. Calculating the Number of Ions in a Sample Section 6.5 Determine the number of calcium and chloride ions in a 32.5 g sample of calcium chloride. Use the given data to complete the calculation. g g g Given: = 32.5 g; MCa = 40.08 ; MCl = 35.45 mol mol mol Required: number of calcium and chloride ions, N and N Solution: Step 1: Calculate the molar mass of calcium chloride, . = 1(MCa) + 2(MCl) = __________ + 2(__________ ) = __________ Ca2+ Cl- Step 2

  13. 1 mol g Calculating the Number of Ions in a Sample Section 6.5 Step 2: Calculate the amount of calcium chloride using an appropriate conversion factor. = __________ g × = __________ mol [carry five decimals] Step 3

  14. formula units 1 mol Calculating the Number of Ions in a Sample Section 6.5 Step 3: Calculate the number of formula units in the 32.5 g sample. = (__________ mol ) ( ) = __________ formula units [carry four decimals] Step 4

  15. 1 calcium ion 1 formula unit 2 chloride ions 1 formula unit Calculating the Number of Ions in a Sample Section 6.5 Step 4: Determine the number of each type of ion present. N = ( __________ formula units) ( ) N= __________ ions N = ( __________ formula units) ( ) N= __________ ions Statement: A 32.5 g sample of calcium chloride contains __________ calcium ions and __________ chloride ions. Ca2+ Ca2+ Cl- Cl-

  16. The Law of Definite Proportions Section 6.6 Imagine water molecules being put one by one into each side of this scale. Click the image on the right to play the animation. What is the difference between the two sides of the scale? What is the same?

  17. The Law of Definite Proportions Section 6.6 Complete the definition below. Click the screen to reveal the answers. Law of Definite Proportions: the statement that a compound always contains the same ___________ of ___________ by ___________ . proportion elements mass

  18. Section 6.6 Discussion: The Law of Definite Proportions How could the law of definite proportions help you to determine a chemical formula from lab data that gave you the ratio of elements in a substance?

  19. 1 mol 1 mol Determining an Empirical Formula Section 6.7 Determine the empirical formula of a compound that contains 56.0% vanadium and 44.0% oxygen. Use the data from the problem to complete the calculation for Step 1. Given: % V = 56.0 %; % O = 44.0 %; MV = 50.94 g/mol; MO = 16.00 g/mol Required: empirical formula of the unknown compound, VxOy Solution Step 1: A 100.0 g sample of this compound contains g of vanadium and __________ g of oxygen. Calculate the amount of each element in the 100.0 g sample. nV= (__________ g ) ( ) nV= __________ mol [carry four decimals] nO= ( __________ g ) ( ) nO= __________ mol [carry four decimals] Step 2

  20. n n n n Determining an Empirical Formula Section 6.7 Step 2: Divide the amount of each element by the smallest amount. = 1 = = __________ = Assign a value of , relative to . Step 3

  21. Determining an Empirical Formula Section 6.7 Step 3: These calculations give an empirical formula of V1O . Multiplying both subscripts by gives V O . Statement: The empirical formula for the compound is .

  22. Chemical Fingerprinting Section 6.8 A mass spectrometer measures the masses of ionized entities by measuring their deflection as they pass through a strong magnetic field. Match the correct tag to each part of the diagram or to the graph. mass spectrum ion source analyzer detector Note

  23. Section 6.8 Note: Chemical Fingerprinting The fragment pattern produced is often unique to a substance, and can be used to identify it.

  24. Section 6.8 Discussion: Chemical Fingerprinting If Canadian scientists wanted to test Canadian currency in a similar procedure to the British, what variable would they have to change? Why?

  25. Determining a Molecular Formula Section 6.9 When you are given percentage composition data for a molecular compound and its molar mass, there are several steps needed to determine the molecular formula for the compound. Rearrange these steps in the correct order. Click the screen for a hint. Then click the screen again for answers. 6 Determine the molecular formula. Determine the simplest ratio for the elements. Solve for the mass multiple. Determine the amount of each element in a 100.0 g sample. Determine the empirical formula. Determine the molar mass of the empirical compound. 2 (Step 2) (Step 5) 5 1 3 4

  26. ANSWERS TEACHER’S NOTES LESSON

  27. Diabetes: Diagnosis and Management Section 6.1 Diabetes is usually diagnosed by tests that reveal excess glucose in a patient’s blood. Diabetes can be managed, often by diet alone, reducing blood glucose back toward normal levels and helping patients lead healthy lives. Match the correct type of analysis to each blood glucose test apparatus. quantitative qualitative

  28. Sodium Ions: Too much of a Good Thing? Section 6.2 • Complete the following statements using the words or phrases below. Sodium ions are needed to help regulate __________ in the body. Excess sodium ions make the body retain __________ which raises _______________. fluid levels water blood pressure 2. Match each quantity of sodium with Health Canada’s description. ● 1500 mg 2300 mg 3400 mg ● average Canadian intake recommended daily intake maximum tolerable limit ● ● ● ●

  29. What’s in a Mole? Section 6.3 Complete each statement by filling in the blank space(s). sucrose • A mole of __________ has a mass of exactly 12 g. • In chemistry, an entity could be an __________, __________, __________, or __________. carbon-12 sodium chloride atom ion molecule formula unit carbon • When measured, 1-mol samples of sucrose, sodium chloride, and carbon have different __________ and volumes, but the same number of __________, 6.02 × 10. masses entities 23 Click the screen for a note: Avogadro’s Constant is 6.02 × 1023.

  30. Calculating Amount from Mass Section 6.4 A portion of French fries contains 1.15 g of sodium chloride, NaCl. Calculate the amount of sodium chloride in 1.15 g. Use the given data to complete the calculation. g g g g g Given: mNaCl = 1.15 g; Mna = 22.99 ; MCl = 35.45 mol mol mol mol mol Required: amount of sodium chloride, nNaCl Solution: Step 1: Calculate to molar mass of sodium chloride, MNaCl. MNaCl = 1(MNa) + 1(MCl) = __________ + __________ MNaCl = __________ 35.45 22.99 Step 2 58.44

  31. Calculating Amount from Mass 1 mol 1 mol g g Section 6.4 Step 2: Multiply the mass of sodium chloride by a conversion factor of . nNaCl = g × nNaCl = mol Statement: There are of sodium chloride in a 1.15 g sample. 58.44 1.15 58.44 0.0196 0.0196

  32. Calculating the Number of Ions in a Sample Section 6.5 Determine the number of calcium and chloride ions in a 32.5 g sample of calcium chloride. Use the given data to complete the calculation. g g g g g Given: = 32.5 g ; MCa = 40.08 ; MCl = 35.45 mol mol mol mol mol Required: number of calcium and chloride ions, N and N Solution: Step 1: Calculate the molar mass of calcium chloride, . = 1(MCa) + 2(MCl) = __________ + 2(__________ ) = __________ Ca2+ Cl- 40.08 35.45 Step 2 110.98

  33. Calculating the Number of Ions in a Sample 1 mol g Section 6.5 Step 2: Calculate the amount of calcium chloride using an appropriate conversion factor. = __________ g × = __________ mol [carry five decimals] 32.5 g 110.98 0.29285 Step 3

  34. Calculating the Number of Ions in a Sample formula units 1 mol Section 6.5 Step 3: Calculate the number of formula units in the 32.5 g sample. = (__________ mol ) ( ) = __________ formula units [carry four decimals] 0.29285 6.03 × 1023 1.7630 × 1023 Step 4

  35. Calculating the Number of Ions in a Sample 1 calcium ion 1 formula unit 2 chloride ions 1 formula unit Section 6.5 Step 4: Determine the number of each type of ion present. N = ( __________ formula units) ( ) N= __________ ions N = ( __________ formula units) ( ) N= __________ ions Statement: A 32.5 g sample of calcium chloride contains __________ calcium ions and __________chloride ions. 1.7630 × 1023 Ca2+ 1.76 × 1023 Ca2+ 1.7630 × 1023 Cl- 3.53 × 1023 Cl- 1.76 × 1023 3.53 × 1023

  36. Determining an Empirical Formula 1 mol 1 mol Section 6.7 Determine the empirical formula of a compound that contains 56.0% vanadium and 44.0% oxygen. Use the data from the problem to complete the calculation for Step 1. Given: % V = 56.0 %; % O = 44.0 %; MV = 50.94 g/mol; MO = 16.00 g/mol Required: empirical formula of the unknown compound, VxOy Solution Step 1: A 100.0 g sample of this compound contains g of vanadium and __________ g of oxygen. Calculate the amount of each element in the 100.0 g sample. nV= (__________ g ) ( ) nV= __________ mol [carry four decimals] nO= ( __________ g ) ( ) nO= __________ mol [carry four decimals] 56.0 44.0 56.0 50.94 g 1.0993 Step 2 44.0 16.00 g 2.7500

  37. Determining an Empirical Formula n n n n Section 6.7 Step 2: Divide the amount of each element by the smallest amount. 1.0993 mol v = 1 = 1.0993 mol v o 2.7500 mol = __________ 2.50 = 1.0993 mol v oxygen 2.50 vanadium Assign a value of , relative to . Step 3

  38. Determining an Empirical Formula Section 6.7 Step 3: These calculations give an empirical formula of V1O . Multiplying both subscripts by gives V O . Statement: The empirical formula for the compound is . 2.5 2 2 5 V2O5

  39. Chemical Fingerprinting Section 6.8 A mass spectrometer measures the masses of ionized entities by measuring their deflection as they pass through a strong magnetic field. Match the correct tag to each part of the diagram or to the graph. analyzer detector ion source mass spectrum

  40. Section 6.1 Answers for Discussion Questions: Slide 5 Sample answer for Discussion:A quantitative instrument allows the diabetic person to compare multiple readings taken at different times, such as before and after meals. These numeric readings allow a diabetic patient to check on her blood glucose level as it varies over time, so she can see how well she is managing her diabetes (for instance, through diet). They let the patient know the amount of glucose in her blood, rather than simply indicating that there is or is not glucose in her blood.

  41. Section 6.1 Answers for Discussion Questions: Slide 7 Sample answer for Discussion:Sodium is an important nutrient for human beings; moreover it occurs naturally in many foods, so getting rid of it entirely would mean processing these foods. However, if less salt were added to processed, packaged foods, many people would find it easier to reduce the amount of sodium they consume.

  42. Section 6.4 Answers for Discussion Questions: Slide 11 Sample answer for Discussion:Calcium chloride has a slightly more complicated chemical formula, CaCl2. So I would need to double the molar mass of chlorine (as well as replacing the molar mass of sodium with that of calcium).

  43. Section 6.6 Answers for Discussion Questions: Slide 16 Answer:The mass of water, the number of water molecules, and the numbers of atoms of each element are all greater on the left. The ratio of hydrogen atoms to oxygen atoms is the same on both sides.

  44. Section 6.6 Answers for Discussion Questions: Slide 18 Sample answer for Discussion: The law of definite proportions means that the ratio of each pair of elements and ions in a chemical compound is always the same, so I could use the ratio to determine a chemical formula that would always be true.

  45. Section 6.8 Answers for Discussion Questions: Slide 23 Sample answer for Discussion: Paper is one of the variables that scientists tried to control in the British experiment. Canadian scientists would have to make sure that their experiment used paper similar to that used in Canadian bills.

  46. Credits Slides 4 and 27: left Photos.com; right Cordelia Molloy/Photo Researchers, Inc. Slides 8 and 29: Dave Starrett

More Related