1. Chapter 10 Chemical Quantities

2. Measuring Matter Matter can be measured by 3 methods Matter can be measured by 3 methods By count By count the number of CDs you have the number of CDs you have The number of atoms or molecules you have The number of atoms or molecules you have By mass or weight By mass or weight You buy vegetables by the pound You buy vegetables by the pound The mass(g) of a compound or element you have The mass(g) of a compound or element you have By volume By volume You buy soda in two liter bottles You buy soda in two liter bottles The number of milliliters of a substance you have The number of milliliters of a substance you have

3. Measuring Matter Every measurement has a MAGNITUDE and DIMENSION Every measurement has a MAGNITUDE and DIMENSION Magnitude is the numerical value Magnitude is the numerical value Dimension is the unit of measurement (gram, pound, etc) Dimension is the unit of measurement (gram, pound, etc)

4. Conversion factors Relationships between two numbers Relationships between two numbers 1 Dozen = 12 things 1 Dozen = 12 things 1 Pair = 2 things 1 Pair = 2 things 1 Minute = 60 seconds 1 Minute = 60 seconds 1000 Meter= 1 kilometer 1000 Meter= 1 kilometer

5. Conversion Factors continued Can also be written as fractions… Can also be written as fractions… 1 dozen 1 dozen 12 things 12 things

6. Dimensional Analysis Using conversion factors (T boxes ) to solve problems is called dimensional analysis Using conversion factors (T boxes ) to solve problems is called dimensional analysis

7. Finding Mass from a Count What is the mass of 90 average-sized apples if a dozen apples has a mass of 2.0kg? What is the mass of 90 average-sized apples if a dozen apples has a mass of 2.0kg? 90 apples 1 dozen 12 apples 2.0kg 1 dozen apples Hint: use “T” box = 15 kg or 15,000g

8. Practice Problems If 0.20 bushel is 1 dozen apples and a dozen apples has a mass of 3.0 kg, what is the mass of 0.50 bushel of apples? If 0.20 bushel is 1 dozen apples and a dozen apples has a mass of 3.0 kg, what is the mass of 0.50 bushel of apples? 7.5 kg or 7500g

9. Assume 3.0 kg of apples is 1 dozen and that each apple has 8 seeds. How many apple seeds are in 14kg of apples? 448 seeds

10. When determining quantities in chemistry the method is the same….. You just use different units !!!!!!!!

11. dimensional analysis activity dimensional analysis activity dimensional analysis activity dimensional analysis activity

12. Chemical Units

13. -mass is measured in a.m.u. (atomic mass units) -Formula mass: the mass of the atoms in the compound in amu - round to the nearest hundredth. Ex. Water HH O 1.01 16.00 Formula Mass= 1.01 +16.00 18.02 a.m.u. Comparing mass of molecules

14. 2. Add them together 1. Multiply # of atoms of each element by its mass (amu) Ex.Fe 2 O 3 Fe = 55.85 x 2 = 111.70 O = 16.00 x 3 = +48.00 = 159.70 amu Finding formula mass:

15. Calculate the formula mass for each of the following: AgNO 3 = KC 2 H 3 O 2 =

16. 1.Calculate the f.m. of compound 2. Calculate the f.m. of H 2 O x # of molecules 3. Add together Formula Mass of Hydrates * Remember f.m. of hydrate includes the mass of the water

17. Step 1: Ba= 1 x 137.33 = 137.33 Cl = 2 x 35.45 = + 70.90 208.23 Ex. BaCl 2 2H 2 O Step 2: H= 2 x 1.01 = 2.02 O= 1 x 16.00 = +16.00 18.02 x 2 =36.04 Step 3: 208.23 + 36.04 = 244.27a.m.u.

18. Ws. Chemical Quantities- Formula Mass

19. But we have a problem….. We can’t measure amu’s in lab so scientists had to come up with a measurement we could use.

20. The Mole Mole = 6.02 x 10 23 particles of a substance – could be atoms, molecules, or formula units Mole = 6.02 x 10 23 particles of a substance – could be atoms, molecules, or formula units Ex: A mole of hydrogen atoms is 6.02 x 10 23 hydrogen atoms, a mole of paper is 6.02 x 10 23 piece of paper Ex: A mole of hydrogen atoms is 6.02 x 10 23 hydrogen atoms, a mole of paper is 6.02 x 10 23 piece of paper 6.02 x 10 23 is known as Avogadro’s number- Avogadro was an Italian scientist in the 1800’s helped clarify the difference between atoms and molecules 6.02 x 10 23 is known as Avogadro’s number- Avogadro was an Italian scientist in the 1800’s helped clarify the difference between atoms and molecules

21. A mole of any substance contains 6.02 x 10 23 representative particles A mole of any substance contains 6.02 x 10 23 representative particles

22. How many atoms of carbon would there be in a mole?

23. How many molecules of water would there be in a mole of water?

24. mole is a unit mole is a unit mole is a unit mole is a unit TedEd TedEd TedEd

25. The Mass of a Mole (MOM) of a substance = formula mass in grams

26. Mass of a Mole The atomic mass of an element expressed in grams is the mass of one mole of that element. The atomic mass of an element expressed in grams is the mass of one mole of that element. Example- 1 mole of carbon is 12.0 grams. Example- 1 mole of carbon is 12.0 grams. The molar mass of any two elements contain the same number of atoms The molar mass of any two elements contain the same number of atoms Ex: a dozen apples – 12 apples Ex: a dozen apples – 12 apples a dozen oranges – 12 oranges a dozen oranges – 12 oranges

27. 1 atom carbon 1 mole of carbon atoms (6.02 x 10 23 atoms) 12.01 amu 12.01 grams Formula Mass Molar mass (MOM)

28. Would a mole of ping pong balls have the same mass as a mole of bowling balls?

29. Would a mole of carbon atoms have the same mass as a mole of sodium atoms? What would a mole of carbon atoms weigh in grams? What would a mole of carbon atoms weigh in grams? What about a mole of sodium atoms? What about a mole of sodium atoms?

30. Mass of a Mole of a Compound Find the number of grams of each element in the compound, then add the masses together. Find the number of grams of each element in the compound, then add the masses together. Ex: Find the molar mass of water. Ex: Find the molar mass of water. Step 1- write down the formula H2O Step 1- write down the formula H2O Step 2- determine masses of each element Step 2- determine masses of each element 2 H atoms x 1.0 g = 2.0 g H 2 H atoms x 1.0 g = 2.0 g H 1 O atom x 16.0 g = 16.0 g O 1 O atom x 16.0 g = 16.0 g O Step 3- add masses together 16.0 g O + 2.0 g H = 18.0 g H2O Step 3- add masses together 16.0 g O + 2.0 g H = 18.0 g H2O The molar mass of water is 18.0 g/mol

31. Cl C HH O Which would have a higher mass…. a mole of water or a mole of carbon tetrachloride?

32. We can use the molar mass of a compound to convert between moles and masses of compounds We can use the molar mass of a compound to convert between moles and masses of compounds

33. Avogadro’s Number (6.02 x 10 23 ) -is the # of atoms in the molar mass of an element. 12.01g Carbon = 6.02 x 10 23 atoms

34. OR - is the # of molecules in the molar mass of a compound. 18.02g H 2 O = 6.02 x 10 23 molecules

35. Finding the Mass of a Mole of a compound The decomposition of hydrogen peroxide (H 2 O 2 ) provides sufficient energy to launch a rocket. What is the molar mass of hydrogen peroxide? The decomposition of hydrogen peroxide (H 2 O 2 ) provides sufficient energy to launch a rocket. What is the molar mass of hydrogen peroxide? 34.02g

36. Practice problems Find the molar mass (MOM) of PCl 3. Find the molar mass (MOM) of PCl 3.137.32g/mol What is the molar mass(MOM) of 1.00 mol sodium hydrogen carbonate? (NaHCO 3 ) What is the molar mass(MOM) of 1.00 mol sodium hydrogen carbonate? (NaHCO 3 )84.01g

37. What if there is more than one mole of the compound?

38. Mole to Mass Conversion Use the molar mass of an element or compound to convert between the mass of a substance and the moles of a substance Use the molar mass of an element or compound to convert between the mass of a substance and the moles of a substance Conversion factor 12 inches = 1 foot Conversion factor 12 inches = 1 foot 3 feet = 1 yard 3 feet = 1 yard molar mass = 1 mole molar mass = 1 mole ex: 18.0 g H2O = 1 mol H2O

39. Mole – Mass Relationship Use the molar mass of an element or compound to convert between the mass and moles of a substance. Use the molar mass of an element or compound to convert between the mass and moles of a substance. ****Remember: ****Remember: molar mass = 1mol

40. Let’s try them with “T” boxes/conversion factors… What is the mass of 3.4 moles of Mg? What is the mass of 3.4 moles of Mg? What is the mass of 23.9 moles of Sn? What is the mass of 23.9 moles of Sn? How many grams are in 18.1 moles of F? How many grams are in 18.1 moles of F? How many grams are in 98.5 moles of Zn? How many grams are in 98.5 moles of Zn? How many grams are in 2.7 x10 2 mol Pb? How many grams are in 2.7 x10 2 mol Pb?

41. Find the mass in grams of 4.52x10 -3 mol of C 20 H 42. Find the mass in grams of 4.52x10 -3 mol of C 20 H 42. 1.27g C 20 H 42 Calculate the mass in grams of 2.50 mol of Iron(II)hydroxide. Calculate the mass in grams of 2.50 mol of Iron(II)hydroxide. 225g Fe(OH) 2

42. What is the mass of 3.0 mol of NaCl? What is the mass of 3.0 mol of NaCl?176g What is the mass of 9.45 mol of Aluminum oxide? What is the mass of 9.45 mol of Aluminum oxide? 964g Al 2 O 3

43. Find the number of moles in 3.70 x10 -1 g of boron. Find the number of moles in 3.70 x10 -1 g of boron. 3.43 x 10 -2 mol B Calculate the number of moles in 75.0 g dinitrogen trioxide. 0.987 mol N 2 O 3

44. Review: Practice problems Moles ↔ Mass

45. Which would have more atoms a mole of carbon or a mole of sulfur ? … both would have 6.02 x 10 23 atoms

46. Converting # of atoms to Moles How many moles of magnesium is 1.25 x 10 23 atoms of magnesium? (hint: use “T” box) 2.08 x 10 -1 mol Mg or 0.208 mol Mg

47. Practice Problems How many moles is 2.80 x 10 24 atoms of silicon? How many moles is 2.80 x 10 24 atoms of silicon? 4.65mol Si 4.65mol Si How many moles is 2.17 x 10 23 representative particles of bromine? How many moles is 2.17 x 10 23 representative particles of bromine? 0.360 mol Br 2

48. Use “T” Boxes to calculate these….. How many moles is 15.38 x 10 23 atoms of Ni? How many moles is 15.38 x 10 23 atoms of Ni? How many moles is 2 x 10 32 atoms of Ti? How many moles is 2 x 10 32 atoms of Ti? How many moles is 17.93 x 10 18 atoms of Be? How many moles is 17.93 x 10 18 atoms of Be? How many moles is 8.7 x 10 23 atoms of Ag? How many moles is 8.7 x 10 23 atoms of Ag?

49. Cl C HH O Which would have more atoms…. a mole of water or a mole of carbon tetrachloride? …so a mole of different compounds can have different numbers of atoms

50. Converting Moles of Compound to Number Of Atoms Is C an element or compound? Is C an element or compound? Element- 1 mole is 6.02 x 10 23 atoms Element- 1 mole is 6.02 x 10 23 atoms Is CO 2 an element or compound? Is CO 2 an element or compound? Compound – 1 mole is 6.02 x 10 23 molecules (or formula units) Compound – 1 mole is 6.02 x 10 23 molecules (or formula units) Remember a mole is 6.02 x 10 23 things !!! Remember a mole is 6.02 x 10 23 things !!!

51. Be careful when counting atoms. Determine if you have an element or a compound Determine if you have an element or a compound If a compound, the moles is the # of molecules If a compound, the moles is the # of molecules You then have to multiply by the # of atoms in that compound You then have to multiply by the # of atoms in that compound

52. Converting Moles of Compound to Number Of Atoms Is C an element or compound? Is C an element or compound? Element- 1 mole is 6.02 x 10 23 atoms Element- 1 mole is 6.02 x 10 23 atoms Is CO 2 an element or compound? Is CO 2 an element or compound? Compound – 1 mole is 6.02 x 10 23 molecules (or formula units) Compound – 1 mole is 6.02 x 10 23 molecules (or formula units) Remember a mole is 6.02 x 10 23 things !!! Remember a mole is 6.02 x 10 23 things !!!

53. Try these - use “T” boxes !!!!! How many atoms in 2.3 moles of C? How many atoms in 2.3 moles of C? How many atoms in 2.3 moles of CO 2 ? How many atoms in 2.3 moles of CO 2 ?

54. Propane is a gas used for heating and cooking. How many atoms are in 2.12 mol of propane (C 3 H 8 )? Propane is a gas used for heating and cooking. How many atoms are in 2.12 mol of propane (C 3 H 8 )? Hint: moles molecules atoms 1.40 x 10 25 atoms

55. Practice Problems How many atoms are in 1.14 mol of SO 3 ? How many atoms are in 1.14 mol of SO 3 ? 2.75 x 10 24 atoms How many moles are in 4.65 x 10 24 molecules of NO 2 ? How many moles are in 4.65 x 10 24 molecules of NO 2 ? 7.72 mol NO 2

56. Ws. Converting Between Mass mole and Number of Particles

57. HW.Ws. More Practice problems: Chemical Quantities

58. Mole-Mass-Volume Relationships

59. Cl C HH O Which would have more molecules in a mole….. water or carbon tetrachloride? … both would have 6.02 x 10 23 molecules

60. Cl C HH O Which would take up more room….. a mole of water or a mole of carbon tetrachloride?

61. ….so a mole of different substances can have different volumes.

62. Molar Volume The volumes of gases do not follow the pattern of liquids and solids. The volumes of gases do not follow the pattern of liquids and solids. Volume of gases change with change in temperature and pressure Volume of gases change with change in temperature and pressure Cold O 2 Hot O 2

63. STP Standard Temperature and Pressure Standard Temperature and Pressure Temperature = 273K (0 o C) Temperature = 273K (0 o C) Pressure =1 atm (101.3kPa) Pressure =1 atm (101.3kPa) If no temperature or pressure are given in a problem, assume the gas is at STP If no temperature or pressure are given in a problem, assume the gas is at STP A balanced equation, shows a gas at STP A balanced equation, shows a gas at STP

64. Molar Volume At STP 1 mol (6.02 x 10 23) any gas occupies a volume of 22.4 Liters At STP 1 mol (6.02 x 10 23) any gas occupies a volume of 22.4 Liters Calculating Volume at STP Calculating molar mass from density

65. 1 mol of a gas at STP Occupies 22.4L Occupies 22.4L 22.4L = molar volume of a gas

66. Calculating Volume at STP Conversion factor is: Conversion factor is: 22.4L= 1 mol at STP 22.4L= 1 mol at STP Ex: Determine the volume in liters of 0.60 mol of SO 2 gas at STP Ex: Determine the volume in liters of 0.60 mol of SO 2 gas at STP 13L SO 2 13L SO 2

67. Ex: sulfur dioxide is a gas produced by burning coal. It is an air pollutant and one of the causes of acid rain. Determine the volume, in liters, of 0.60 moles of sulfur dioxide gas at STP. Ex: sulfur dioxide is a gas produced by burning coal. It is an air pollutant and one of the causes of acid rain. Determine the volume, in liters, of 0.60 moles of sulfur dioxide gas at STP.

68. 13 L does this make sense? 13 L does this make sense?

69. Practice Problems What is the volume of 3.20 x 10 -3 mol of CO 2 (g) at STP? 7.17 x10 -2 L CO 2 7.17 x10 -2 L CO 2 What is the volume of 3.70 mol of N 2 (g) at STP? What is the volume of 3.70 mol of N 2 (g) at STP? 82.9LN 2 82.9LN 2

70. More Practice At STP, what volume does 1.25 mol He gas occupy? At STP, what volume does 1.25 mol He gas occupy? 28.0L He 28.0L He At STP what volume does 0.335mol C 2 H 6 gas occupy? At STP what volume does 0.335mol C 2 H 6 gas occupy? 7.50L C 2 H 6 7.50L C 2 H 6

71. Ws. Chemical Quantities (boxes)

72. Calculating Molar Mass from Density Different gases have different densities. Different gases have different densities. ***Remember density unit is g/L ***Remember density unit is g/L Ex. helium vs. nitrogen Ex. helium vs. nitrogen To calculate the molar mass of a gas you need: To calculate the molar mass of a gas you need: Density of gas at STP and volume of gas at STP Conversion factor 22.4L Conversion factor 22.4L 1 mol 1 mol

73. Practice problems The density of a gaseous compound containing carbon and oxygen is 1.964g/L at STP. What is the molar mass of the compound? The density of a gaseous compound containing carbon and oxygen is 1.964g/L at STP. What is the molar mass of the compound? D= grams 1.964 g 22.4liter D= grams 1.964 g 22.4liter liter 1 liter1 mole liter 1 liter1 mole 44g/mol 44g/mol

74. More Practice A gaseous compound of sulfur and oxygen which is linked to the formation of acid rain, has a density of 3.58g/L. What is the molar mass of this gas? A gaseous compound of sulfur and oxygen which is linked to the formation of acid rain, has a density of 3.58g/L. What is the molar mass of this gas? 80.2g/mol 80.2g/mol

75. Each stoppered flask below contains 2 liters of a gas at STP. Does each gas sample have the same …… (explain each- * hint set up “T” boxes) (a) mass ? (b) density ? (c) number of molecules ? (d) number of atoms ?

76. Volume of Gas (STP) Representative Particles Mass Molar mass 1.00 mol 1.00 mol molar mass 1.O0 mol 6.02 x10 23 particles 6.02 x10 23 particles 1.00 mol 1.00 mol 22.4 L 22.4L 1.00mol mole

77. Percent Composition

78. percent by mass percent by mass % composition = Mass of element x 100% % composition = Mass of element x 100% mass of compound mass of compound

79. When you see %, think…… Part Whole X 100 = %

80. Sample Problem Propane (C 3 H 8 ) is one of the lighter compounds obtained from petroleum. Calculate the percent composition of propane. (when they ask for % composition, they want the % of each thing in it) Propane (C 3 H 8 ) is one of the lighter compounds obtained from petroleum. Calculate the percent composition of propane. (when they ask for % composition, they want the % of each thing in it) %C= Mass of C mass of propane X 100 = 81.8% %H= Mass of H mass of propane X 100 =18%

81. Try this….. Calculate the % Nitrogen in the following compound Calculate the % Nitrogen in the following compound Ammonium nitrate (NH 4 NO 3 )

82. Ammonium nitrate: N= 35% Ammonium nitrate: N= 35%

83. Don’t forget about the Law of Conservation of Mass (matter)

84. Sample Problem When a 13.60g sample of a compound containing only magnesium and oxygen is decomposed, 5.40g of oxygen is obtained. What is the percent composition of this compound? When a 13.60g sample of a compound containing only magnesium and oxygen is decomposed, 5.40g of oxygen is obtained. What is the percent composition of this compound? % Mg = Mass of Mg mass of compound X 100 % O = Mass of O mass of compound X 100 =60.3% = 39.7% ** % of elements should add up to 100%

85. Practice Problems A compound is formed when 9.03g Mg combines completely with 3.48g N. What is the % composition of this compound? A compound is formed when 9.03g Mg combines completely with 3.48g N. What is the % composition of this compound? 72.2%Mg and 27.8% N 72.2%Mg and 27.8% N When a 14.2g sample of mercury(II) oxide is decomposed into its elements by heating, 13.2g Hg is obtained. What is the % composition of the compound? When a 14.2g sample of mercury(II) oxide is decomposed into its elements by heating, 13.2g Hg is obtained. What is the % composition of the compound? 7.0%O and 93.0% Hg 7.0%O and 93.0% Hg

86. Watch the Hydrates !!! CuSO 4 5H 2 0 CuSO 4 5H 2 0

87. Practice :% composition from the formula Ws. Percent Composition Ws. Percent Composition

88. Percent composition as a conversion factor Multiply the mass of the compound by a conversion factor based on the percent composition in the compound. Multiply the mass of the compound by a conversion factor based on the percent composition in the compound.

89. The Percent Composition of a Compound Percent Composition from the Chemical Formula Percent Composition from the Chemical Formula 10.3

90. Ex: How many grams of hydrogen are are contained in a 100 gram sample of of propane? (the formula for propane is C 3 H 8 ? Ex: How many grams of hydrogen are are contained in a 100 gram sample of of propane? (the formula for propane is C 3 H 8 ?

91. The Percent Composition of a Compound Propane (C 3 H 8 ) is 81.8% carbon and 18% hydrogen. You can calculate the mass of carbon and the mass of hydrogen in an 82.0 g sample of C 3 H 8. Propane (C 3 H 8 ) is 81.8% carbon and 18% hydrogen. You can calculate the mass of carbon and the mass of hydrogen in an 82.0 g sample of C 3 H 8. 10.3

92. Molecular formula – the actual # of atoms in the compound Ex. C 6 H 12 O 6 glucose Empirical Formula – The simplest formula in whole #’s Ex. CH 2 O glucose Empirical Formula vs. Molecular Formula

93. Empirical Formulas Empirical formula- lowest whole number ratio of atoms of the elements in a compound Empirical formula- lowest whole number ratio of atoms of the elements in a compound Ex. H 2 O 2 hydrogen peroxide Ex. H 2 O 2 hydrogen peroxide Empirical formula = HO Empirical formula = HO Ex. H 2 O water Ex. H 2 O water Empirical formula and molecular formula are the same Empirical formula and molecular formula are the same

94. To Calculate Empirical Formula % to mass (assume you have 100g) % to mass (assume you have 100g) Mass to moles Mass to moles Divide by small Divide by small Multiply ‘til whole Multiply ‘til whole

95. Empirical Formulas Ethyne (C 2 H 2 ) is a gas used in welder’s torches. Styrene (C 8 H 8 ) is used in making polystyrene. Ethyne (C 2 H 2 ) is a gas used in welder’s torches. Styrene (C 8 H 8 ) is used in making polystyrene. These two compounds of carbon have the same empirical formula (CH) but different molecular formulas. These two compounds of carbon have the same empirical formula (CH) but different molecular formulas. 10.3

96. If masses are given… just start with “ Mass to mole” step

97. Ws. Determining the Empirical Formula for Compounds

98. What do these have in common? CH 2 O CH 2 O C 2 H 4 O 2 C 2 H 4 O 2 C 4 H 8 O 4 C 4 H 8 O 4 C 6 H 12 O 6 C 6 H 12 O 6 What is different about them ?

100. Molecular Formulas 10.3

101. Calculating empirical formula from % composition Ex: Cisplatin is the common name for a platinum compound used to treat cancerous tumors has the composition (in mass percent) of 65.02% Pt, 9.34% N, and 23.63% Cl. Calculate the empirical formula for cisplatin. Ex: Cisplatin is the common name for a platinum compound used to treat cancerous tumors has the composition (in mass percent) of 65.02% Pt, 9.34% N, and 23.63% Cl. Calculate the empirical formula for cisplatin..

102. 1. determine how many grams of each element are present in a 100 g sample of a compound. (convert % to grams) 1. determine how many grams of each element are present in a 100 g sample of a compound. (convert % to grams) Ex: there is 65.02 grams of platinum per 100 g of compound, 9.34 g N, 2.02 g H. Ex: there is 65.02 grams of platinum per 100 g of compound, 9.34 g N, 2.02 g H. 2. Convert mass to moles of each using the molar mass of the elements 2. Convert mass to moles of each using the molar mass of the elements Ex. 0.3333 mol Pt Ex. 0.3333 mol Pt 0.667 mol N 0.667 mol N 2.00 mol H 2.00 mol H 0.6666 mol Cl 0.6666 mol Cl

103. Step 3 : Divide through by the element with the lowest number of moles Step 3 : Divide through by the element with the lowest number of moles 0.3333 mol Pt0.667 mol N 2.00 mol H 0.3333 mol Pt0.667 mol N 2.00 mol H 0.6666 mol Cl 0.6666 mol Cl

104. If formula (molecular) mass is given…. Calculate empirical formula Calculate empirical formula Calculate the molar mass of the empirical formula Calculate the molar mass of the empirical formula Divide the formula (molecular) mass by the empirical molar mass to see how many times you need to multiply the subscripts. Divide the formula (molecular) mass by the empirical molar mass to see how many times you need to multiply the subscripts.

105. A compound contains 40% carbon, 6.6% hydrogen and 53.4% oxygen. It has a molecular mass of 90 grams What is the empirical formula? What is the empirical formula? What is the molecular formula? What is the molecular formula?

106. Ws. Molecular and Empirical Formulas #1-7 Ws. Molecular and Empirical Formulas #7-13

108. Calculation of molecular formula

109. Molecular Formulas Molecular Formulas Molecular Formulas How does the molecular formula of a compound compare with the empirical formula? How does the molecular formula of a compound compare with the empirical formula? 10.3

110. The molecular formula of a compound is either the same as its experimentally determined empirical formula, or it is a simple whole-number multiple of its empirical formula. The molecular formula of a compound is either the same as its experimentally determined empirical formula, or it is a simple whole-number multiple of its empirical formula.

112. 10.12

113. 10.12

114. Section Quiz.

115. 1. Calculate the percent by mass of carbon in cadaverine, C 5 H 14 N 2, a compound present in rotting meat 1. Calculate the percent by mass of carbon in cadaverine, C 5 H 14 N 2, a compound present in rotting meat 67.4% C 67.4% C 58.8% C 58.8% C 51.7% C 51.7% C 68.2% C 68.2% C

116. 2. Which of the following is NOT an empirical formula? 2. Which of the following is NOT an empirical formula? NO 2 NO 2 H 2 N H 2 N CH CH C 3 H 6 C 3 H 6 10.3 Section Quiz.

117. Section Quiz. Section Quiz. 3. Determine the molecular formula of a compound that contains 40.0 percent C, 6.71 percent H, and 53.29 percent O and has a molar mass of 60.05 g. 3. Determine the molecular formula of a compound that contains 40.0 percent C, 6.71 percent H, and 53.29 percent O and has a molar mass of 60.05 g. C 2 H 4 O 2 C 2 H 4 O 2 CH 2 O CH 2 O C 2 H 3 O C 2 H 3 O C 2 H 4 O C 2 H 4 O

118. B,d,a B,d,a