1. Bellwork
Solve the following using dimensional analysis and place the answer in scientific notation.
1. Jamie has 2.5 liters of mercury in a jar. What is the mass of this mercury if its density is 13.6 g/ml?

2. CHAPTER 10 THE MOLE

3. The mole (mol) is one of the seven base units in the SI system
The mole (mol) is one of the seven base units in the SI system. It measures the amount of substance.

4. The form in which a substance exists is its “representative particle”
The form in which a substance exists is its “representative particle”. Representative particles can be atoms, ions, molecules, formula units, or anything else.

5. Just as one dozen is 12 representative particles of eggs, a mole is 6
Just as one dozen is 12 representative particles of eggs, a mole is 6.02 x 1023 representative particles.
602,000,000, 000,000,000, 000,000!!!!!

6. You can have a mole of ANYTHING!!
Examples: 1 mole Fe = 6.02 x 1023 atoms of Fe 1 mole H2O molecules = 6.02 x 1023 molecules of water 1 mole NaCl formula units = 6.02 x 1023 NaCl formula units 1 mole eggs = 6.02 x 1023 eggs
You can have a mole of ANYTHING!!

7. How much is a mole? 6.02 X 1023 Watermelon Seeds:
Would be found inside a melon slightly larger than the moon.
6.02 X Donut Holes:
Would cover the earth and be 5 miles (8 km) deep.
6.02 X Pennies:
Would make at least 7 stacks that would reach the moon.
6.02 X Grains of Sand:
Would be more than all of the sand on Miami Beach.
6.02 X Blood Cells:
Would be more than the total number of
blood cells found in every human on earth.
How much
is a mole?

8. Question
How many molecules would be in 3 moles of water?

9. Diatomic Elements Certain elements are only stable in pairs or with other elements in a compound. These elements are called the diatomic elements.

10. There are 7 diatomic elements: Bromine, Iodine, Nitrogen, Chlorine, Hydrogen, Oxygen, and Fluorine (Memory trick: HBrONClIF or 7th Heaven)

11. Avogadro’s Number. 6. 02 x 1023 is called Avogadro’s number
Avogadro’s Number *6.02 x 1023 is called Avogadro’s number. *It is named after Amadeo Avogadro who did work in the 1800’s that allowed x 1023 to be calculated.

12. The mole is the “chemist’s dozen”
The mole is the “chemist’s dozen”. It is a convenient way to count extremely large numbers of atoms, molecules or ions.

13. New Conversion Factor. 1 mole = 6
New Conversion Factor! 1 mole = 6.02 x 1023 representative particles We work these problems using dimensional analysis.

14. How many moles are 1.20 x 1025 atoms of phosphorous?
1.20 x 1025 atoms P 1 mol P x 1023 atoms
= 19.9 mol P

15. How many atoms are in 0.750 mol of Zn?
0.750 mol Zn x 1023 atoms Zn = mol Zn
4.52 x 1023 atoms Zn

16. How many molecules are in 0.400 mol N2O5?
Q: What did Avogadro teach his students in math class?
0.400 mol N2O x 1023molecules = mole N2O5
2.41 x 1023 molecules
A: Moletiplication

17. How many moles are contained in 1.20 x 1024 molecules CO2?
1.20 x 1024 molec CO mol CO x 1023 molecules
= 1.99 moles CO2

18. Question
Your friend gives you a gold ring that contains 2.3 mol of atoms. How many atoms is this?

19. Gram atomic mass (gam) -atomic mass of an element in grams -mass of one mole of atoms of a monatomic element

20. Question Write the atomic masses of the following. Mg __________
Cl ___________
Ba ___________

21. Example:
C =12.0 g = mass of 6.02 x 1023atoms
12.0 g/mol is the gram atomic mass of carbon

22. Molar mass (M.M.) is a term used to describe the mass of a mole of a chemical compound.

23. Molar Mass (M.M.) -mass of one mole of any compound -sum of the atomic masses of each atom in the compound
1 mol H2O: 2 mol H mol O =2 mol H x g H/mol = g =1 mol O x g O/mol= g g H2O

24. Question
What is the gram molecular mass of P2O5?

25. What is the molar mass of CH3OH?
C 1 x =
H 4 x =
O 1 x = g

26. Quiz day
Get ready for your quiz!!!
Test on Wednesday!

27. What is the M.M. of magnesium phosphate?
Mg3(PO4)2
3 mol Mg 3 x g = g
2 mol P x g = g
8 mol O x g = g g

28. What is the molar mass of ammonium sulfate?
(NH4)2SO4
2 mol N 2 x =
8 mol H 8 x =
1 mol S 1 x =
4 mol O 4 x = g

29. Mole – Mass Conversions New Conversion factor
Mole – Mass Conversions New Conversion factor! mol = molar mass ( grams)

30. Find the mass in grams of 3.32 mol of K.
3.32 mol K g K mol K
= x 102 g K

31. Find the mass in grams of 15.0 mol of sulfuric acid.
H2SO4
H 2 x = S 1 x = O 4 x = g
15.0 mol H2SO g H2SO mol H2SO4
= 1470 g H2SO4

32. Find the number of moles in 11.0 g of methane (CH4).
CH4 = (12.011g g = g)
11.0 g CH4 1 mol CH g CH4
= mol CH4
What was Avogadro’s favorite Indian tribe?
The MOLEHICANS

33. Bellwork
What is the molar mass of methane? Methane’s formula is CH4

34. Molti-Step Mole Problems!
Calculate the number of molecules present in 4.29 g of nitrogen dioxide (NO2).
4.29 g NO mol NO x1023 m.c. NO2=
g NO2 1 mol NO2
= 5.61x1022 molecules NO2

35. Molti-Step Mole Problems!
Calculate the number of moles of sulfur atoms present in 2.01 g of sodium sulfide (Na2S).
2.01 g Na2S 1 mol Na2S mol S atoms
g Na2S 1 mol Na2S
= mol S atoms

36. Molti-Step Mole Problems!
Calculate the mass in grams of 2.49 x 1020 carbon dioxide (CO2) molecules.
2.49 x 1020 CO2 m.c. 1 mol CO g CO2
6.02x1023 m.c.CO2 1 mol CO2
= 1.82 x 10-2 grams CO2

37. Molti-Step Mole Problems!
Calculate the grams of carbon in 12.2 mol sucrose, C12H22O11.
12.2 mol C12H22O mol C atoms g C
1 mol C12H22O mol C atoms
= 1.76 x 103 g carbon

38. Question
Write the two conversion factors we have discussed below. Show how they are related.

39. Molar Volume of a Gas The volume of a gas is usually measured at 0oC and 1 atmosphere of pressure. This is called standard temperature and pressure (STP).

40. -At STP, one mole of any gas has a volume of 22
-At STP, one mole of any gas has a volume of 22.4 L which is called the molar volume of a gas and contains x 1023 particles of the gas L of a gas has a mass equal to the gfm of the gas. -So… 1 mol = 22.4L = 6.02 x 1023 particles = M.M.

41. New conversion factor. 1 mol of any gas at STP = 22
New conversion factor! 1 mol of any gas at STP = 22.4 L (for gases only)

42. What is the volume (liters) at STP of 0.960 mol of methane, CH4?
0.960 mol CH L CH mol CH4
= 21.5 L CH4

43. At STP, how many moles are in 0.542 mL of neon gas?
0.542 mL Ne 1 L Ne mol Ne mL Ne L Ne
= 2.42 x 10-5 mol Ne

44. Question
Relate the three conversion factors we have learned below.

45. Bellwork
Jake has a jar full of sodium hydrogen carbonate, or baking soda (NaHCO3). What is the mass of 2.78 mol baking soda?

46. Bellwork
How many propane molecules are in g of propane, C3H8?

47. Percent Composition (remember: percent = part divided by total x 100) percent by mass of each element in a compound

48. What is the percent composition of NO2?
N 1 x =
O 2 x =
( /46.005g)x100 =30.4%Ca
( /46.005g)x100 =69.6% C
46.005
100%
As long as your % adds up to % you are fine.

49. Why is Avogadro so rich!
Because he is a multi-mole-ionairre!!!!

50. What is the percent composition of calcium acetate?
Ca(C2H3O2)2
Ca1 x40.078=40.078
C 4 x12.011=48.044
H 6 x = 6.048
O 4 x15.999=63.996 g
( / g)x100=25.3% Ca
( / g)x100=30.4% C
( / g)x100=3.8% H
( / g)x100=40.5% O
100.0%

51. Calculate the number of grams of calcium in 9.7 g of calcium acetate?
Ca(C2H3O2)2
= 2.46 g Ca
9.7 g Ca(C2H3O2)2
25.4 g Ca
100 g Ca(C2H3O2)2

53. Bellwork
Susannah has 12.5g of HC2H3O2, or vinegar. How many MOLECULES of vinegar does she have?

55. CALCULATING EMPIRICAL FORMULAS Empirical formula - lowest whole number ratio of the elements in a compound - may or may not be the same as the molecular formula.

56. Empirical Formula Poem Percent to mass, mass to moles,
Steps to calculate empirical formula: 1. Find moles of each element. 2. Set up mole ratio.
Empirical Formula Poem
Percent to mass,
mass to moles,
divide by smallest and round ‘till whole!
3. Simplify mole ratio (divide by smallest). If your answers are not in whole numbers, you must multiply by 2,3,4,or 5 to get whole numbers. 4. Use mole ratio as subscripts in the formula. If given % composition, assume 100 g of compound.

57. A compound is 79.8% C and 20.2% H. Find its empirical formula.
/6.65 = 1
79.8gC 1mol C = mol C
g C
20.2 g H 1 mol H = 20.0 mol H
1.008 g H
CH3
/6.65 = 3

59. Find the empirical formula for a compound made up of 26. 7% P, 12
Find the empirical formula for a compound made up of 26.7% P, 12.1% N and 61.2% Cl.
26.7 g P 1 mol P = mol P g P
12.1 g N 1 mol N = mol N g N
61.2 g Cl 1 mol Cl = mol Cl
g Cl
/0.862=1
/0.862=1
/0.862=2
Empirical Formula = PNCl2

60. Bellwork
NutraSweet is 57.14% C, 6.16% H, 9.52% N, and 27.18% O.  Calculate the empirical formula of NutraSweet.

61. Molecular formulas are the actual formulas
Molecular formulas are the actual formulas. They may be the same as the empirical formula or a multiple of it.

62. To find the multiple (n), take the molar mass (M. M
To find the multiple (n), take the molar mass (M.M.) and divide by the empirical formula mass (efm): n = M.M efm
Multiply each subscript in the empirical formula by n to get the molecular formula.

63. A white powder is analyzed and found to have the empirical formula P2O5. The compound has a molar mass of g. What is the compound’s molecular formula?
P2O5 = g/mol
M.M./efm
283.9 g/mol
g/mol = 2
2(P2O5) = P4O10

64. A compound used as an additive for gasoline to help prevent engine knock shows the following percentage composition: % Cl 24.27% C 4.07% H The molar mass is known to be g. Determine the empirical formula and the molecular formula for this compound.
/2.02 = 1
71.65 g Cl 1 mol Cl = 2.02 mol Cl
g Cl
24.27g C 1 mol C = 2.02 mol C
g C
4.07g H 1 mol H = 4.04 mol H
1.008 g H
1:1:2 ClCH2 or CH2Cl
efm = =49.48 g/mol
98.96/49.48= C2H4Cl2
/2.02 = 1
/2.02 = 2

67. Hydration Water of hydration – water in a crystal
When copper (II) sulfate is dissolved in water and then the water allowed to evaporate, copper (II) sulfate pentahydrate is formed
CuSO4 + 5H2O ↔ CuSO45H2O
Hydrate - compound that contains water of hydration
Dot used to connect formula of compound and # of water molecules per unit
CoCl2 is blue
CoCl2•6H2O is red
Give them words have them predict products/reactants
The picture above shows copper (II) sulfate pentahydrate. Notice the water molecules surrounding the copper molecules.

68. Hydration
When cobalt (II) chloride is dissolved in water and then the excess water is allowed to evaporate, cobalt (II) chloride hexahydrate is formed
CoCl H2O
↔ CoCl2 6H2O

69. In the hydrate CuSO4.5H20, how many water molecules would be present in 3 formula units?

70. Naming Hydrates To name a hydrate, use the following:
They are named by giving the name of the salt followed by a prefix that stands for the number of water molecules associated with a formula unit of the salt.
Ex: CuSO4 • 5H2O
copper (II) sulfate
penta
hydrate

71. Bellwork
How many moles of each substance are contained in the following samples? Be sure to include the correct units and sig figs in your answers.
a) 6.0 x 1020 molecules of carbon dioxide
b) x 1013 molecules of water
c) 5 x 1046 molecules of methane (CH4)

72. Bellwork
You have 10.0 g of aluminum and 73.0 g of gold. Which sample contains more total atoms, the aluminum or gold?

73. Bellwork
What is the molecular formula for a compound that is 46.16% carbon, 5.16% hydrogen and 48.68% fluorine if the molar mass of this compound is g?

74. Bellwork
What is the empirical formula for a compound that contains 17.34% hydrogen and 82.66% carbon?