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1 You must choose 4 for mid-term
Review Book & Mid-Term Topics covered to date: Topic 1 – Atoms Topic 2 – Formulas and Equations Topic 3 – Chemistry Math Topic 4 – Matter Topic 5 – Periodic Table Topic 6 - Bonding You must choose 4 for mid-term

2 Stoichiometry AKA Chemistry Math

3 How many atoms are in a mole of carbon?
BELL RINGER “my avogadro don't want none unless you've got moles hun” How many atoms are in a mole of carbon?

4 Ridiculous Mole Facts 3 moles of M&M’s would fill the entire earths oceans (an equivalent amount of water would fill about a ¼ cup) 1 mole of donut holes will cover the earth to a depth of seven miles! 1 mole of pennies would reach to the moon 7-8 times.

5 A one liter bottle of water contains 55.5 moles of water.
Ridiculous Mole Facts One mole of seconds is about 19 quadrillion years, 4,240,666 times the age of the earth, or 954,150 times the age of the universe itself. A one liter bottle of water contains 55.5 moles of water. If you started with a mole of pennies and spent $1,000,000 every second for 100 years, you would still have more than 99.99% of what you started with. 

6 Are all moles created equally?
VS In chemistry, how an atom reacts is dependent on the number of atoms, not the mass of the atoms. For example, if you have g of Na and react that with g of Chlorine they would not react completely. Chlorine starts out with a mass of 35.5 and Na has a mass of 23 As a result, we would have a bunch of Na atoms unused. In chemistry it is much easier to use a quantity of atoms rather than a mass of atoms

7 A nice mole song! Avogadro Style

8 That would be 6.02 x 1023 atoms of carbon
Moles What is the mass of a Carbon atom? 12.0 amu If one mole of Carbon atom’s have a mass of 12.0g, how many atoms would that be? That would be 6.02 x 1023 atoms of carbon

9 Gram Formula Mass (molar mass)
= the mass of one mole of something Let’s try out water: H2O Therefore, 1 mole of water has a mass of 18g/mol. H 2 x 1.0 = 2.0 = O 1 x 18.0 g/mol

10 GFM (practice) Let’s try magnesium hydroxide: Mg(OH)2 Mg 1 x 24.3
= O 2 x = H 2 x = 58.3 g/mol

11 GFM - Hydrates Na2CO3●10H20 Sodium Carbonate crystals: Na 2 x 23.0
Hydrate - is a crystalline compound in which ions are attached to one or more WATER molecules Na2CO3●10H20 Sodium Carbonate crystals: Na 2 x = C 1 x = 3 x = H20 10 x = 286.0 g/mol

12 “my avogadro don't want none unless you've got moles hun”
BELL RINGER “my avogadro don't want none unless you've got moles hun” What is the gfm of NH4? GFM = 18 Moles = 72.0 ÷ 18.0 = 4 moles

13 Converting to moles 1. Determine the gfm: 18 g/mol
If you have 63g of water how many moles of water do you have? 1. Determine the gfm: 18 g/mol Number of moles given mass (g) gram-formula mass = Number of moles 63g 18g/mol = = 3.5 moles

14 Conversions Moles to Grams
1. How many g are in moles of H2O2? Number of moles given mass (g) gram-formula mass = 2. How many g are in 1.20 moles of CaCO3?

15 GFM Practice 1. NaBr 6. C6H12O6 2. PbSO4 7. Fe3(PO4)2 3. Ca(OH)2
8. (NH4)2S 4. Na3PO4 9. Zn(C2H3O2)2 5. (NH4)2CO3 10. AgF

16 GFM Practice 1. NaBr 6. C6H12O6 2. PbSO4 7. Fe3(PO4)2 3. Ca(OH)2
102.9 g/mol 180.0 g/mol 2. PbSO4 7. Fe3(PO4)2 303.3 g/mol 357.4 g/mol 3. Ca(OH)2 8. (NH4)2S 74.1 g/mol 68.1 g/mol 4. Na3PO4 9. Zn(C2H3O2)2 164.0 g/mol 183.4 g/mol 5. (NH4)2CO3 10. AgF 126.9 g/mol 96.0 g/mol

17 You have 72.0g of NH4. How many moles do you have?
BELL RINGER You have 72.0g of NH4. How many moles do you have? GFM = 18.0 Moles = 72.0 ÷ 18.0 = 4.00 moles

18 Copper (II) sulfate●pentahydrate Sodium Hydrogen Carbonate
GFM Whiteboard Review Zinc Copper (II) sulfate●pentahydrate Sodium Hydrogen Carbonate Sucrose C12H22O11 Sodium Carbonate Iron Sodium Chloride Water Aluminum

19 Some Practice What is the gfm for Calcium nitrate? Ca 1 x 40.1 = 40.1
Criss-cross to get the formula: Ca(NO3)2 Ca 1 x = N 2 x = O 6 x = 164.1 g/mol 2. How many moles of calcium nitrate do you have if you have 10.2 g? Number of moles given mass (g) gram-formula mass = Number of moles 10.2g 164.1g/mol = = moles

20 Practice Problems GFM = 122.6 g GFM = 122.6 g
1. If you have 40.8g of KClO3. How many moles do you have? GFM = g Number of moles given mass (g) gram-formula mass = Number of moles 40.8 g 122.6g = = moles 2. You have 2.5 moles of KClO3. How many grams is that? GFM = g Grams = GFM x # moles Grams = 122.6g/mol x 2.5 moles = g = 310 g

21 Percent Composition What are the % of elements in dihydrogen monoxide?
-used to find the percentage by mass of an element in a compound What are the % of elements in dihydrogen monoxide? H2O H 2 x 1.0 = 2.0 %= 2.0/18.0 = 11% 1 x 16.0 = 16.0 O %= 16.0/18.0 = 88.9% 18.0 g

22 Percent Composition What are the % of elements in potassium nitrate?
KNO3 K 1 x 39.1 = % = /101.1 = 38.7% N 1 x 14.0 = 14.0 % = /101.1 = 13.8% = O 3 x 16.0 % = 48.0/101.1 = 47.5% 101.1 g

23 Hydrate Percent Composition
What is the percentage of water in the following compound CoCl2•6H2O Co 1 x 58.9 = 58.9 % = /237.9 = 24.8% Cl 2 x 35.5 = 71.0 % = /237.9 = 29.8% = 108.0 H2O 6 x 18.0 % = 108.0/237.9 = 45.40% 237.9 g/mol

24 Hydrate Percent Composition CaSO4•5H2O
What is the percentage of water in the following compound CaSO4•5H2O Ca 1 x 40.1 = 40.1 S 1 x 32.1 = 32.1 O 4 x 16.0 = 64.0 H2O 5 x 18.0 = 90.0 % = 90.0/226.2 = 39.8% 226.2 g/mol

25 How many grams is 0.36 moles of potassium permanganate?
BELL RINGER How many grams is 0.36 moles of potassium permanganate?

26 Empirical and Molecular Formulas
Empirical Formula = the formula of a compound expressed as the smallest possible whole-number ratio of subscripts of the elements in the formula Molecular Formula = the formula of a compound in which the subscripts give the actual number of each element in the formula

27 Empirical and Molecular Formulas
Empirical Formula H2O CH3COOH CH2OH WO2 B2H6 C6H12O6 H2O CH2O CH2OH WO2 BH3 CH2O

28 Empirical and Molecular Formulas
A compound with an empirical formula of C2OH4 and a molar mass of 88 grams per mole. What is the molecular formula of the compound?

29 Empirical and Molecular Formulas
A well known reagent in analytical chemistry, dimethylglyoxime, has the empirical formula C2H4NO. If its molar mass is 116.1g/mol, what is the molecular formula of the compound?

30 Popcorn Lab

31

32 BELL RINGER What are the empirical formulas for the following? C6H6 CH2ClCH3 HC2H3O2

33 Determining Formulas from %
Percent to mass Mass to moles Divide by small Multiply ‘til whole A compound consists of 72.2% magnesium and 27.8% nitrogen by mass. What is the empirical formula? 1. Assume 100g, so you have: 72.2g Mg and 27.8g N 2. Convert to moles Mg /24.3 = 2.97 moles N – 27.8/14.0 = 1.99 moles

34 Determining Formulas from %
Percent to mass Mass to moles Divide by small Multiply ‘til whole 3. Divide by small Mg / 1.99 = 1.49 Mg1.49N1.00 ??? N / 1.99 = 1.00 4. Multiply ‘til whole Mg 1.49 X 2 = 3 Mg3N2 N 1 X 2 = 2

35 Hydrate Problem In lab, a student determined that a hydrate of barium chloride contained 14.0% water. What is the actual numbers of water molecules for each molecule of barium chloride. Basically the formula of the hydrate. REMEMBER

36 Hydrate Problem Barium Chloride Water 14.0%

37 Hydrate Lab

38 BELL RINGER Problem: A compound contains 32.4% sodium, 22.1% sulfur and 45.0% oxygen. What is the empirical formula? Na 32.4g S 22.1g O 45.0g ÷ 23.0 ÷ 32.1 ÷ 16.0 = 1.41 mol = mol = 2.81 mol ÷ .688 = 2.05 = 1.00 = 4.09 As a result the formula would be: Na2SO4

39 3.56 g. Use this information to determine the formula for the hydrate.
Hydrate Practice A calcium chloride hydrate has a mass of 4.72 g. After heating for several minutes the mass of the anhydrate is found to be 3.56 g. Use this information to determine the formula for the hydrate.

40 Hydrate Practice (lab problem)
Mass of Hydrate = 4.72g Anhydrous = 3.56g Calcium Chloride Water

41 CHEMICAL REACTIONS Reactants: Zn + I2 Product: Zn I2

42 Chemical Equations Because of the principle of the law conservation of matter, an equation must be balanced. It must have the same number of each kind of atoms on both sides. Lavoisier 1788

43 Al (s) + O2 (g) ---> Al2O3 (s)
Chemical Equations Their Job: Depict the kind of reactants and products and their relative amounts in a reaction. Al (s) O2 (g) ---> Al2O3 (s) The numbers in the front are called stoichiometric ____________ 4 3 2 coefficients

44 Symbols Used in Equations
Solid (s) Liquid (l) Gas (g) Aqueous solution (aq) Catalyst H2SO4 Escaping gas () Change of temperature ()

45 but you may not change the subscripts.
Balancing Equations When balancing a chemical reaction you may add coefficients in front of the compounds to balance the reaction - but you may not change the subscripts. Changing the subscripts changes the compound. Subscripts are determined by the valence electrons (charges for ionic or sharing for covalent)

46 Subscripts vs. Coefficients
The subscripts tell you how many atoms of a particular element are in a compound. The coefficient tells you about the quantity, or number, of molecules of the compound.

47 Why are we learning this?
The coefficients of a chemical reaction indicate relative amounts of reactants and products. Coefficients are MOLE RATIOS Example: H2(g) + Cl2(g)  2HCl(g) 1 mol H2 : 1 mol Cl2 : 2 moles HCl The relative masses of the reactants and products can also be determined from the coefficients. Example: 1 mol H2 = 2.02 g H2 1 mol Cl2 = g Cl2 2 mol HCl = g HCl Therefore, 2.02g H2 will react with 70.90g Cl2 to form 72.92g of HCl.

48 Steps to Balancing Equations
Compare the numbers of atoms on each side of the equation Start with the most complicated molecules FIRST! Leave H and O until the end Place COEFFICIENTS in front of the compound to try and balance the atoms Check your answer to see if: - The numbers of atoms on both sides of the equation are now balanced. Reduce if possible!!!!

49 Steps to Balancing Equations
2 3 ___ Al(s) + ___ Br2(l) ---> ___ Al2Br6(s)

50 Online Balancing Equations
Click on picture above to go to the site!

51 Balancing Equations 5 ____C3H8(g) _____ O2(g) > _____CO2(g) _____ H2O(g) 3 4 ____B4H10(g) _____ O2(g) > ___ B2O3(g) _____ H2O(g) 2 11 4 2 10 5

52 KMnO4 + HCl = KCl + MnCl2 + H2O + Cl2
K4Fe(CN)6 + H2SO4 + H2O = K2SO4 + FeSO4 + (NH4)2SO4 + CO C6H5COOH + O2 = CO2 + H2O K4Fe(CN)6 + KMnO4 + H2SO4 = KHSO4 + Fe2(SO4)3 + MnSO4 + HNO3 + CO2 + H2O Cr2O7{-2} + H{+} + {-} = Cr{+3} + H2O S{-2} + I2 = I{-} + S PhCH3 + KMnO4 + H2SO4 = PhCOOH + K2SO4 + MnSO4 + H2O CuSO4*5H2O = CuSO4 + H2O

53 Balancing Equations 2 2 ___ H2(g) + ___ O2(g) ---> ___ H2O(l)
What Happened to the Other Oxygen Atom????? This equation is not balanced! Two hydrogen atoms from a hydrogen molecule (H2) combines with one of the oxygen atoms from an oxygen molecule (O2) to form H2O. Then, the remaining oxygen atom combines with two more hydrogen atoms (from another H2 molecule) to make a second H2O molecule.

54 BELL RINGER Balance the following: Sodium phosphate + iron (III) oxide  sodium oxide + iron (III) phosphate 2 Na3PO4 + Fe2O3 ----> Na2O FePO4 3 2

55 Balance the following: Ca(OH)2 + H3PO4 → Ca3(PO4)2 + H2O
BELL RINGER Balance the following: Ca(OH)2 + H3PO4 → Ca3(PO4)2 + H2O

56 Balancing wkst

57 Practice Balancing Equations
2 __Al + __O2  __Al2O2 __ Fe + __Cl2  __ FeCl3 2 3 2 3 __Fe2O3 + __H2SO4  __Fe2(SO4)3 + __H2O 3 __KClO3 → __KCl + __O2 2 2 3

58 Methane reacts with oxygen to produce carbon dioxide and water
Practice Write out the following chemical equation  Methane reacts with oxygen to produce carbon dioxide and water CH4 + O2 CO2 + H2O

59 Practice H2(g) + O2(g)  + H2O(l) energy
Write out the following chemical equation  Hydrogen gas reacts in the presence of oxygen gas to explode and produce liquid water. H2(g) + O2(g) H2O(l) + energy

60 What is the IUPAC name of the following compound? Mn2O3
BELL RINGER What is the IUPAC name of the following compound? Mn2O3

61 Chemical Equations 4 Al(s) + 3 O2(g) ---> 2 Al2O3(s)
This equation means 4 Al atoms + 3 O2 molecules ---produces---> 2 molecules of Al2O3 AND/OR 4 moles of Al + 3 moles of O produces---> 2 moles of Al2O3

62 Types of Reactions There are five types of chemical reactions we will talk about: Synthesis reactions Decomposition reactions Combustion reactions Single replacement reactions Double Replacement reactions You need to be able to identify the type of reaction and predict the product(s)

63 Zn powder + Sulfur – See Hilt
1. Synthesis Reactions Synthesis reactions occur when two substances (generally elements) combine and form a compound. (Sometimes these are called combination or addition reactions.) reactant + reactant  1 product Basically: A + B  AB Example: 2H2 + O2  2H2O Example: C + O2  CO2 DEMO: Write the reaction for the synthesis of MgO(s) Mg(g) + O2(g)  MgO(s) 2 Zn powder + Sulfur – See Hilt

64 2. Decomposition Reactions
Decomposition reactions occur when a compound breaks up into the elements or in a few to simpler compounds 1 Reactant  Product + Product In general: AB  A + B Example: 2 H2O  2H2 + O2 Example: 2 HgO  2Hg + O2

65 Decompostion of KBrO3 – See Hilt
Elephant’s Toothpase Write the reaction for the decomposition of hydrogen peroxide (H2O2) H2O2  H2O O2 2 Decompostion of KBrO3 – See Hilt

66 Practice Predict the products. Then, write and balance the following decomposition reaction equations: Solid Lead (IV) oxide decomposes The formation of sulfur dioxide PbO2(s)  Pb + O2 S + O2  SO2

67 3. Combustion Reactions Combustion is actually an organic reaction
Organic Compound + O2  CO2 + H2O Methane Mamba CH4 + O2  CO2 + H2O

68 BELL RINGER Write and balance the following: Decomposition of ammonia Formation of calcium chloride

69 4. Single Replacement Reactions
Single Replacement Reactions occur when one element replaces another in a compound. A metal can replace a metal (+) OR a nonmetal can replace a nonmetal (-). Must refer to Table J element + compound different element + different compound A + BC  AC + B (if A is a metal) OR A + BC  BA + C (if A is a nonmetal) (remember the cation(+) always goes first!) When H2O splits into ions, it splits into H+ and OH- (not H+ and O-2 !!)

70 Aluminum metal reacts with aqueous copper (II) nitrate
Practice Sodium chloride solid reacts with fluorine gas NaCl(s) + F2(g)  2 NaF(s) + Cl2(g) Aluminum metal reacts with aqueous copper (II) nitrate Al(s) + 2 3 Cu(NO3)2 (aq)  Cu + 3 2 Al(NO3)3

71 5. Double Replacement Reactions
Double Replacement Reactions occur when a metal replaces a metal in a compound and a nonmetal replaces a nonmetal in a compound Compound + compound  product + product AB + CD  AD + CB

72 Double Replacement Reactions
Mixed doubles in tennis, can the guy switch with a girl? Example: AgNO3(aq) + NaCl(s)  AgCl(s) + NaNO3(aq)

73 Double Replacement Reactions
Lead (II) Nitrate and Potassium Iodide  Lead (II) Iodide and Potassium Nitrate Pb(NO3)2 + 2 KI PbI2 + 2 KNO3

74 RB: p. 40 q ODD only

75 BELL RINGER Predict the following products and ID the reaction type: MgCl2 + NaOH 

76 Aluminum metal reacts with fluorine gas
Practice Predict the product. Write and balance the following synthesis reaction equations. Aluminum metal reacts with fluorine gas Al(s) F2(g)  3 2 AlF3

77 Types of Reactions Lab

78 Types of Reactions Lab AND NO GARBAGE!
You need to make sure your tray has: 1 Test tube rack 4 test tubes Box of matches 10 ml Graduated cylinder Watch glass Test tube tongs Crucible tongs Scoopula Wood splint Plastic spatula Microspatula AND NO GARBAGE!

79 Mole Calculations

80

81 For the Scan-Tron p. 53+54 1 – 45 2 – 46 3 – 47 4 – 48 5 – 49 6 – 50
7 – 51 8– 52 9– 53 10– 54 11– 55 12– 56 13– 57 14 – 58 15 – 59 16 – 60 17 – 61 18 – 62 19 – 63 20 – 64 21 – 65 22 – 66 23 – 67 24 – 68 25 – 69 26 – 70 27 – 71

82 BELL RINGER Write and balance the following: Magnesium and oxygen react to form magnesium oxide.

83 HW Quiz Decomposition of Aluminum oxide Synthesis of sulfur trioxide
Combustion of Methane (CH4) Sodium bromide and silver nitrate form sodium nitrate and silver bromide. Balance the following: C6H12O6  C2H5OH + CO2

84 Are you smarter than a 5th Grader ….
Lila decided to make more baked goods for the bake sale. She used 1/8 lb less flour to make bread than to make cookies. She used ¼ lb more flour to make cookies than to make brownies. If she used ½ lb of flour to make the bread, how much flour did she use to make the brownies?

85 Stoichiometry A way to predict how many products can be made or how many reactants would be needed. You need to get the equation written correctly and balanced properly. 2H2 + O2  2H2O For example: You would need 2 moles of Hydrogen to make 2 moles of water 1 mole of oxygen would make 2 moles of water If you made 6 moles of water, how much hydrogen would you need? 6 moles What would the mass of that be?  12 grams If you had 12 moles of oxygen and 2 moles of hydrogen, how much water could you make? 2 moles of water

86 Stoichiometry 2 3 AuCl3  Au + Cl2
How many moles of gold can be liberated from the decomposition of 5.2 moles of gold (III) chloride? AuCl3  Au Cl2 2 3 Mass GFM Moles ? 5.20 mol 5.20 mol Setup mole ratio

87 Stoichiometry 2 3 AuCl3  Au + Cl2
How many grams of Chlorine can be liberated from the decomposition of 64.0g of gold(III) chloride? AuCl3  Au Cl2 2 3 Mass GFM Moles 64.0g ? 22.5 g 303.5g/mol 71.0 g/mol .211 mol .317 mol Setup mole ratio

88 Stoichiometry 2 3 AuCl3  Au + Cl2
How many grams of gold can be liberated from the decomposition of 0.50 moles of gold (III) chloride? AuCl3  Au Cl2 2 3 Mass GFM Moles ? 98.5 g 197.0 g/mol 0.50 mol 0.50 mol Setup mole ratio

89 How many grams is 1.25 moles of Sodium hydroxide
BELL RINGER How many grams is 1.25 moles of Sodium hydroxide GFM = 40 Moles = 1.25 x 40 = 50 g

90 BELL RINGER Gold (III) Chloride breaks into its component elements. Write the balanced equation for this reaction.

91 BELL RINGER Al + O2  Al2O3 What is the total number of moles of O2 that must react completely with 8.0 moles of Al in order to form Al2O3?

92 Don’t panic – Balance the equation
Stoichiometry How many moles of carbon dioxide are needed to produce moles of glucose in the following reaction: CO H2O  C6H12O O2 6 Mass GFM Moles 2.00mol ? 0.333 mol Setup mole ratio Don’t panic – Balance the equation

93 Stoichiometry What mass of carbon dioxide is needed to react with 54.0g of water in the following reaction: CO H2O  C6H12O O2 6 Mass GFM Moles ? 54.0g 132.0 g 44.0 g/ mol 18.0g/mol 3.00 mol 3.00 mol Setup mole ratio Don’t panic – Balance the equation Must convert to moles – NEVER grams

94 BELL RINGER KClO3(s)  KCl(s) + O2(g) If you have 20.0 g of potassium chlorate, how many moles of oxygen could you make?

95 Practice Predict the products. Balance the equation
1. HCl(aq) + AgNO3(aq)  HNO3(aq) + AgCl(s) 2. CaCl2(aq) + Na3PO4(aq)  3 2 6 NaCl(aq) + Ca3(PO4)2(s) 3. Pb(NO3)2(aq) + BaCl2(aq)  PbCl2(s) + Ba(NO3)2(aq) 4. FeCl3(aq) + NaOH(aq)  3 Fe(OH)3(s) + NaCl(aq) 3 5. H2SO4(aq) + NaOH(aq)  2 2 HOH + Na2SO4(aq) 6. KOH(aq) + CuSO4(aq)  K2SO4(aq) + Cu(OH)2(s) 2

96

97 BELL RINGER Write the balanced equation for the decomposition of potassium chlorate.

98

99 BELL RINGER If you wanted to make moles of hydrogen gas from the decomposition of water, how many moles of water would you need to start with?

100 Mixed Practice State the type, predict the products, and balance the following reactions: BaCl2 + H2SO4  C6H12 + O2  Zn + CuSO4  Cs + Br2  FeCO3 

101 To get Molecular Formula from Empirical Formula
Problem: You know a compound has an empirical formula of CN and a molecular mass of 52.0g. What is the molecular formula? Find the mass of the empirical formula C – N – 14 = 26 How many times does that mass divide into the molecular mass? 52 / 26 = 2 Multiply that number to each element in the empirical formula C2N2

102 Determining Formulas from %
Hydrated Crystals A student starts with 25.0 g of Barium Chloride Hydrate. The student performs the lab and has 21.4 g of anhydrous salt. What was the original formula of the hydrated crystal? 1. You already have g so you do not have to assume g. 2. Convert to moles BaCl2  g/mol Salt – 21.4 g ÷ g/mol = mol H2O – 3.6 g ÷ g/mol = 0.20 mol

103 Determining Formulas from %
Hydrated Crystals Percent to mass Mass to moles Divide by small Multiply ‘til whole 3. Divide by small Salt  ÷ 0.103 = 1 BaCl2• ?H2O H2O  ÷ = 1.94 4. Multiply ‘til whole Do Not need to here! Just Round BaCl2• 2H2O


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