Warm-Up. If I weigh 200 pounds, how many pounds of oxygen make up my body? How much hydrogen?

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1 Warm-Up What are the percentage compositions (by mass) of the following elements in the human body? 1. Oxygen 2. Carbon 3. Hydrogen 4. Nitrogen 5. Calcium (65%) (18%) (10%) (3%) (1.5%) If I weigh 200 pounds, how many pounds of oxygen make up my body? How much hydrogen?

2 Warm-Up Phosphorus (1.0%) Potassium (0.35%), Sulfur (0.25%) Sodium (0.15%), Magnesium (0.05%) December Copper, Zinc, Selenium, Molybdenum, Fluorine, Chlorine, Iodine, Manganese, Cobalt, Iron (0.70%) Lithium, Strontium, Aluminum, Silicon, Lead, Vanadium, Arsenic, Bromine (trace amounts)

3 Monday, December 7, 2015 Today: Intro to % Composition HW: Study for GFM and %Comp Quiz on Wednesday

4 Percent Composition A comparison of the mass of one element to the whole compound. Steps: 1. Find the GFM. 2. Divide the mass of each element by the GFM. What is the percent mass of each element in K 2 SO 4?

5 Question What is the percent composition (by mass) of hydrogen in water? What do we need to know?

6 Percent Composition A comparison of the mass of one element to the whole compound. Steps: 1. Find the GFM. 2. Divide the mass of each element by the GFM.

7 Percent Composition If the total percentages add up to less than 99 or more than 101 you should check your calculations for errors.

8 Practice Find the percent composition for each element in phosphoric acid (H 3 PO 4 ). H = 1 x 3 = 3 3/97.9 x 100 = 3.1% P = /97.9 x 100 = 31.7% O = 16.0 x 4 = /97.9 x 100 = 64.4%

9 More Practice Find the percent composition for each element in potassium nitrate. K = N = O = KNO 3

10 One More Find the percent composition for each element in calcium iodide. CaI 2

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12 Gram Atomic Mass The mass of one mole of an element is found on the periodic table. For example: One mole of iron is Sodium = Nitrogen = Nitrogen gas = N 2 = 2 x = 28.02

13 Gram Formula Mass The gram formula mass is found by adding the atomic masses for each element. For example, the formula mass for CaSO 4 is: Element Ca S O GFM = Atomic Mass x 4 = g/mol

14 Gram Formula Mass Gram Formula Mass is the same as Molar Mass

15 Gram Formula Mass HCl NaOH Mg(OH) 2 Mg 3 (PO 4 ) 2

16 Gram Formula Mass Find the gram formula mass for NaOH = The GFM for (NH 4 ) 2 CO 3 = The molar mass for (NH 4 ) 2 CO 3 = Complete the Gram Formula Mass table in you notes.

17 Percent Composition A comparison of the mass of one element to the whole compound. Steps: 1. Find the GFM. 2. Divide the mass of each element by the GFM.

18 Percent Composition For example: find the percent composition of copper in copper (II) sulfate. 1. Find GFM for CuSO4 2. Find percentage Cu = /159.5 = 0.39 x 100 = 39% S = /159.5 = 0.20 x 100 = 20% O = 16.0 x 4 = 64 64/159.5 = 0.40 x 100 = 40% GFM = Total = 100%

19 Percent Composition A comparison of the mass of one element to the whole compound. Steps: 1. Find the GFM. 2. Divide the mass of each element by the GFM.

20 Percent Composition If the total percentages add up to less than 99 or more than 101 you should check your calculations for errors.

21 Practice Find the percent composition for each element in phosphoric acid (H 3 PO 4 ). H = 1 x 3 = 3 3/97.9 x 100 = 3.1% P = /97.9 x 100 = 31.7% O = 16.0 x 4 = /97.9 x 100 = 64.4%

22 More Practice Find the percent composition for each element in potassium nitrate. K = N = O = KNO 3

23 One More Find the percent composition for each element in calcium iodide. CaI 2

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25 Tuesday, December 8, 2015 Today: Lab: Percent Composition of Sugar in Gum HW: Study for GFM and %Comp Quiz on Wednesday

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27 Wednesday November 15, 2006 Today: W-Up, Notes & Practice: The Mole HW: p 287, #53, 54a,b, 58a,b,c -- write question, show work.

28 Warm Up 1. Find the percent composition of hydrogen in water. Find the % comp of oxygen in water. 2. An 8.2 g piece of magnesium combines completely with 5.40 g of oxygen to form a compound. What is the percent composition of each element in the compound?

29 GFM Quiz and Key Zn(OH) 2 = g/mol Nitric Acid = HNO 3 = H 2 S = Sodium (s) Na =22.99 magnesium chloride MgCl 2 = sulfur dioxide SO 2 = Hydrochloric Acid HCl = HgCl = (NH 4 ) 2 C 2 O 4 = Ethane C 2 H 6 = 30.26

30 Amedeo Avogadro. Hot or Not? Image from enc/fecs/avogadro.htm

31 Amedeo Avogadro Avogadro s number = 6.02 x particles 1 mole has 6.02 x particles

32 The Mole The Mole is the basic unit of chemistry. - also called Avogadro s Number - abbreviated mol - there are 6.02 x particles in a mole

33 The mole is important because - it is convenient to work with. - allows us to count atoms. - let s us compare numbers of atoms in chem rxns In general it just makes life easier. We don t have to work with huge numbers like all the time.

34 Some Practice 1 mol of grains of sand =? grains of sand 1 mol of eggs =? _ eggs 1 mol of atoms =? _ atoms 2 mol of atoms =? _ atoms

35 So We need to be able to convert from moles to grams.

36 Conversion Factors Allows us to easily convert between different units. For example: $1 = 4 Quarters and 4 Quarters = $1 So 4 Quarters = 1 $1 and $1 4 Quarters = 1

37 Conversion Factors 4 Quarters $1 $1 and 4 Quarters are called conversion factors. How many quarters are in $11? How many dollars are in 82 quarters? How many quarters are in $27?

38 Moles to # Molecules Conversion factors to use: 1 mole 6.02 x molecules or 6.02 x molecules 1 mole -- Convert 2 moles of CuSO 4 to molecules. -- Convert x molecules H 2 O to moles.

39 Moles Grams Conversion factors to use: 1 mole GFM or GFM 1 mole -- Convert 2 moles of CuSO 4 to grams. -- Convert 36.0 grams H 2 O to moles.

40 Steps to Success - Identify what you are given. - Identify what you are being asked to find. - Set up the problem to cancel out quantities. - Write neatly and circle your answer.

41 Practice 1. Convert 0.50 moles of nitric acid to grams. 2. Convert 72.0 grams of magnesium chloride to moles. 3. Convert 80.5 g of ethane to moles. 4. Convert 2.5 moles of sodium chloride to grams. 5. Convert 454 grams of Actinium (atomic number 89) to molecules. Hint: 1 mole = 6.02 x molecules.

42 Moles Gas Liters Conversion factors to use: 1 mole gas 22.4 L or 22.4 L 1 mole gas -- Convert 2 moles of H 2 to liters. -- Convert 44.8 liters O 2 to moles.

43 Start Back of gnotes

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47 Thursday, December 10, 2015 Today: Warm-Up, Practice with Mole Conversions HW: Study for Mole Quiz Fri

48 Warm-Up 1. Find the GFM for hydrochloric acid. 2. Find the molar mass for Al(NO 3 ) 3 3. Find the GFM for sodium hydroxide.

49 Warm-Up 1. What is the mass of 0.5 moles of copper metal? 2. How many moles are in 39.0 grams of K 2 SO 4? 3. How many liters are in 10 mole N 2?

50 Practice Chemical Quantities Mole Practice Problems. doc

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53 Friday December 11, 2015 Today: Warm-Up, Practice, Quiz

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57 More Content

58 Warm-Up 1. What is the percent composition of the elements in C 6 H 10 O 4? 2. How many moles is 21.0 grams of AgCl? 3. How many liters are in 2.0 moles of H 2 gas?

59 Warm-Up

60 --fcards

61 6.02 x Particles Avogadro s Number 1 mole

62 moles grams multiply by GFM

63 grams moles divide by GFM

64 1 MOLE 6.02 x Particles

65 SI Abbreviation for Mole mol

66 GFM Gram Formula Mass

67 1 mole of a gas occupies: 22.4 Liters