2. Bling Bling: if I were to give each of you one atom of gold for every second that has elapsed since the Dinosaur’s went extinct 65 million years ago, how much gold would you have?

3. Moles Not to be confused with this very happy individual.
In Chemistry a mole is defined as 6.022x1023 particles of a substance.

4. How many eggs are in a dozen?
How many apples are there in a dozen?
If a dozen students get detention, how many students have detention?
Dozen = 12 units

5. Moles 6.022 x 1023 is known as Avogadro’s number.
Just as a dozen of any substance equals 12 units of that substance, a mole of any substance equals x 1023 units of that substance.
Avogadro came up with the idea that equal volumes of different gases as STP have the same number of particles….this led to scientists coming up with a more precise number…
Avogadro’s Number (symbol N) is the number of atoms in grams of carbon.
We determine a mole using electric charge (among other means). If we know the charge of one electron and the total charge of one mole of a substance very accurately, we can calculate the number of electrons in a mole of electrons. Avogadro’s number is a MEASURED number.

6. Avogadro’s number is a MEASURED number.
Avogadro: equal volumes of different gases at STP have the same number of particles
Avogadro’s Number is the number of atoms in grams of carbon.
If we know the charge of one electron and the total charge of one mole of a substance very accurately, we can calculate the number of electrons in a mole of electrons.

7. Fe MOLAR MASS The atomic mass of iron is 55.85 AMUs.
1s22s22p63s23p64s23d6 26 Fe
IRON
55.85
The atomic mass of iron is AMUs.
This number also represents the molar mass of Iron.
Iron has a mass of grams per mole.

8. Fe MOLAR MASS This is the molar mass of any single element Unit: g/mol
1s22s22p63s23p64s23d6 26 Fe
IRON
55.85
This is the molar mass of any single element
Unit: g/mol

9. What is the molar mass of
Gold
Mercury
Argon
Oxygen
Sulfur
Hydrogen

10. What is the molar mass of
Gold
Mercury
Argon
Oxygen
Sulfur
Hydrogen
197g/mol
200.6g/mol
39.95g/mol
32g/mol (diatomic)
32.07g/mol
2g/m (diatomic)

11. Au Ag Concept Check How many atoms are there in a mole of gold atoms?
How many atoms are there in a mole of silver atoms? 79 Au
Gold
197 47 Ag
Silver
107.9

12. Au Ag Concept Check 1 mol = 6.022 x1023 units
How many atoms are there in a mole of gold atoms?
How many atoms are there in a mole of silver atoms? 79 Au
Gold
197 47 Ag
Silver
107.9
1 mol = x1023 units

13. Give me One Mole of Iron
If I asked you for one mole of iron, how would you do it?

14. Weigh out 55.85g of iron
How many atoms of iron would you be giving me?
A mol is defined as x 1023 particles 26 Fe
IRON
55.85

15. Give me 3.63 moles of iron?
If I asked you for 3.63 moles of iron, how would you do it?

16. The same way you would give me 4 dozen of something
By Using Conversion Factors

17. Converting 3.63 Moles Fe to grams

18. How many moles is 512 grams of iron?
We solve this again using conversion factors and the molar mass of iron.

19. Converting 512g Fe to moles.

20. How many atoms are in 9.17mol Fe?

21. How many moles are in 25 x 1024 atoms of Fe?

22. Mole Worksheets
1, 2

23. Compounds have Molar Mass
1g/mol
16g/mol
1g/mol + 1g/mol + 16g/mol = 18g/mol

24. Table Salt NaCl Na+ Cl- 23g/mol 35.5g/mol
23g/mol g/mol =58.5g/mol

25. 12(12g/mol) + 22(1g/mol) + 11(16g/mol) = 342.3g/mol
Molar Mass of Sucrose
C12H22O11 C H O
12(12g/mol)
22(1g/mol)
11(16g/mol)
12(12g/mol) (1g/mol) (16g/mol) = 342.3g/mol

26. Molar Mass of Magnesium Nitrate
Mg(NO3)2 Mg N O
24.3g/mol
2(14.01g/mol)
6(16g/mol)
24.3g/mol (14.01g/mol) (16g/mol) = 148.3g/mol

27. Mole worksheet 3

28. Molecular Mass
Molar mass is for the average atomic mass but molecular is for a single molecule but atoms come in different isotopes….

29. How many moles is 512g of water?
Convert 512g H20 ---> moles

30. We can Convert Molecules
Convert 7.5mol H20 ---> grams

31. Rust weakens an iron chain.

32. These aluminum satellite dishes at the National Radio Astronomy Observatory near Soccoro, New Mexico are naturally protected from corrosion by the formation of a thin film of aluminum oxide (Al2O3).

33. Activity: 1 Cup of Water ~236ml
How many grams is it?
What is its molecular mass?
How many moles is it?
How many molecules of H2O are there?
How many total atoms?
All you need for this is a periodic table and a calculator

34. Worksheet 4

35. Moles and Volume at STP
STP = Standard Temperature and Pressure
TEMPERATURE:  K (0 °C, 32 °F)
PRESSURE: 100 kPa ( psi, atm, 1 bar).
Remember: volume is proportional to temperature!

36. Calculating Gas Density
What is the density of ammonia gas, NH3, at STP?
First we need the molar mass for ammonia;
(1.01) = g/mol
The molar volume NH3 at STP is 22.4 L/mol.
Density is mass/volume:
= g/L
17.04 g/mol
22.4 L/mol

37. Calculating Gas Density
What is the density of, O2, at STP?
First we need the molar mass for O2;
2(16g/mol) = 32 g/mol
The molar volume O2 at STP is 22.4 L/mol.
Density is mass/volume:
= 1.4 g/L
32 g/mol
22.4 L/mol

38. Calculating Gas Volume
What is the Volume of 5 moles of He at STP?
First we need the molar mass for He;
He = 4 g/mol
The molar volume of He at STP is 22.4 L/mol.

39. Calculating Moles From Volume
How many moles is 5 Liters of N2 gas at STP?
The molar volume of N2 at STP is 22.4 L/mol.

40. Molar Mass of a Gas
We can also use molar volume to calculate the molar mass of an unknown gas.
1.96 g of an unknown gas occupies 1.00L at STP. What is the molar mass?
We want g/mol, we have g/L.
1.96 g
1.00 L
22.4 L
1 mole ×
= g/mol

41. Mole Unit Factors We now have three interpretations for the mole:
1 mol = 6.02 × 1023 particles
1 mol = molar mass
1 mol = 22.4 L at STP for a gas
This gives us 3 unit factors to use to convert between moles, particles, mass, and volume.

42. Mole-Volume Calculation
A sample of methane, CH4, occupies 4.50 L at STP. How many moles of methane are present?
We want moles, we have volume.
Use molar volume of a gas: 1 mol = 22.4 L
4.50 L CH4 ×
= mol CH4
1 mol CH4
22.4 L CH4

43. Mass-Volume Calculation
What is the mass of 3.36 L of ozone gas, O3, at STP?
We want mass O3, we have 3.36 L O3.
Convert volume to moles then moles to mass:
3.36 L O3 × ×
22.4 L O3
1 mol O3
48.00 g O3
= 7.20 g O3

44. Molecule-Volume Calculation
How many molecules of hydrogen gas, H2, occupy L at STP?
We want molecules H2, we have L H2.
Convert volume to moles and then moles to molecules:
0.500 L H2 ×
1 mol H2
22.4 L H2
6.02×1023 molecules H2
1 mole H2 ×
= 1.34 × 1022 molecules H2

45. Conclusions
Avogadro’s number is 6.02 × 1023 and is one mole of any substance.
The molar mass of a substance is the sum of the atomic masses of each element in the formula.
At STP, 1 mole of any gas occupies 22.4 L.

46. Conclusions Continued
We can use the following flow chart for mole calculations:

47. Bling Bling: if I were to give each of you one atom of gold for every second that has elapsed since the Dinosaur’s went extinct 65 million years ago, how much gold would you have?