1. Is the SI base unit use to measure the amount of a substance.
THE MOLE:
Is the SI base unit use to measure the amount of a substance.
Ex: 1 mol H2(g) or
H2(g) or
5 H2O (l)
5 mol H2O(l)
3 mol NaCl(s) or
3 NaCl(s)

2. 2 mol of H (atoms)
1 mol H2O(l)
1 mol of O (atoms)
6 mol of H (atoms)
3 mol H2O(l)
3 mol of O (atoms)

3. 4 mol Al3+ (ions) 2 mol Al2O3 6 mol O2- (ions)

4. Calculating the number of mole of particles in a compound

5. Ex. How many moles of oxide ions are in 1.5 mol Al2O3.
1st 1 mol Al2O mol O2- ions.
2nd 1.5 mol Al2O3 × 3 mol O2- ions/mol
= 4.5 mol O2- ions.
(Answer)
(Make sense?)

6. THE MOLE ? (1 mol) 1 mol (atoms) = (# of “particles”)
A ream of paper =
500 sheets
A box of pencils =
12 pencils
A pack of candies =
50 candies
A bottle of aspirins =
100 tablets
(1 mol)
(# of “particles”)
1 mol (atoms) =
6.02 × atoms

7. 1 mol = 6.02 × 1023 particles (Avogadro’s Number)

8. 1 mol = 6.02 × 1023 particles (Avogadro’s Number)
atoms (Cu)
particles

9. 1 mol = 6.02 × 1023 particles (Avogadro’s Number)
atoms (Cu)
molecules (CO2)
particles

10. 1 mol = 6.02 × 1023 particles (Avogadro’s Number)
atoms (Cu)
molecules (CO2)
particles formula units (NaCl)

11. 1 mol = 6.02 × 1023 particles (Avogadro’s Number)
atoms (Cu)
molecules (CO2)
particles formula units (NaCl)
ions (Fe2+)

12. 1 mol = 6.02 × 1023 particles (Avogadro’s Number)
atoms (Cu)
molecules (CO2)
particles formula units (NaCl)
ions (Fe2+)
electrons (e-)

13. How large the Avogadro’s Number is ?
1 mol of atoms = 6.02 × 1023 atoms
Could you count the number of atoms in 1 mol?
If you are able to count one atom per second,
6.02 × 1023 ÷ 3600 sec =
1.67 × 1020 hours
1.67 × 1020 hours ÷ 24 days =
6.96 × 1018 days
6.96 × 1018 days ÷ 365 years =
1.91 × 1016 years
19, 100, 000, 000, 000, 000 years !!!
(19 pentillion one hundred quadrillions of years !!!)

14. Mole –to– Number of Particles Conversions:

15. Calculate the number of molecules in 1.5 mol of H2O.
1.5 mol of H2O x Factor
1.5 mol of H2O x
= 9.0 x molecules of H2O

16. You can use proportions:
Or just multiply the number of particles given by the Avogadro’s Number:
1.5 mol x 6.02 × 1023 molec./mol
= 9.0 × 1023 molecules
You can use proportions:
1 mol x 1023 molec.
X = 1.5 mol x 6.02 x 1023 molec.
1 mol
1.5 mol X
Or you can use the equation:
n(x) =

17. You can use proportions:
You can use proportions:
1 mol x 1023 molec.
X = 1.5 mol x 6.02 x 1023 molec.
1 mol
1.5 mol X
Or using equation:
n(x) =

18. Number of Particles –to– Mole Conversions:

19. Calculate the number of moles in 1.806 x 1024 atoms of copper.
1.806 x atoms of Cu x Factor
1.806 x atoms of Cu x
= 0.3 x mol
= mol of Cu

20. Or just divide the number of particles given by the Avogadro’s Number:
x =
= 0.3 × 101 mol Cu = 3.00 mol Cu

21. Calculating the number of particles in a compound

22. Ex. How many atoms of each element there are in 2.5 mol of N2O4?
1st Calculate the # of mol of each element:
Nitrogen (N):
2.5 mol (N2O4) × 2 mol (N)/mol N2O4 =
2nd Calculate the # atoms present:
x 6.02×1023 atoms (N)/mol = =
= 5 mol (N)
5 mol (N)
30.1 × 1023 =
3.01 × 1024 atoms (N)

23. Oxygen (O):
2.5 mol (N2O4) × 4 mol (O)/mol (N2O4)
x ×1023 atoms (O)/mol =
10 mol (O)
10 mol (O) =
= 60.2 × 1023 =
6.02 × 1024 atoms (O)

24. Mass and Mole.

25. Molar Mass: Is the mass in grams of one mole of any pure substance.
Atomic masses --- P. Table)

26. Atomic mass (Na) = 22.99 a.m.u.(atomic mass units)
Molar mass (Na) = g/mol
1 mol (Na) = g
1 mol (Na) = g = 6.02 × atoms.

27. Mole – to - Mass conversions.

28. Determine the number of moles in 60.75 g of magnesium.
60.75 g (Mg) x factor
60.75 g (Mg) x
= mol (Mg)
Answer
Make sense?

29. Or divide the mass given by the molar mass:
= mol (Mg)
Answer

30. The molar mass of a compound:
M(x)

31. The molar mass of a compound
Is the mass (in grams) of one mole of a compound
It represents the sum of the masses of every particle that makes up the compound.

32. Example:
Calculate the molar mass of Na2SO4.
M(Na2SO4) = m (Na) + m (S) + m (O)
= 2(22.99 g) + 1(32.06 g) + 4(16.00 g)
= g g g
M(Na2SO4) = g/mol.

33. Mole – to - Mass conversions in a compound:

34. Calculate the mass of 3.25 mol of H2SO4.
1st – Calculate its molar mass:
M(H2SO4) = m (H) + m (S) + m (O)
= 2(1.01 g) + 1(32.06 g) + 4(16.00 g)
= 2.02 g g g
= g/mol. (Molar Mass)
2nd – Convert the 3.25 mol to g:
3.25 mol (H2SO4) × g (H2SO4)/mol
= 319 g (H2SO4) -- Answer

35. Volume and Mole.

36. Molar Volume: 1 mol = 22.4 dm3 (L) (For any gas at STP)
STP – Standard temperature
& pressure
(0oC & 1 atm)
zzxxSXZX

37. Mole –to– Volume Conversion:

38. Calculate the volume of 0.881 mol of a gas at STP.
V = mol x factor
V = 19.7 L
Answer

39. Or multiply the number of mole given by the Molar Volume:
0.881 mol × 22.4 L/mol
V = 19.7 L

40. Volume –to–Mole Conversion:

41. How many moles of nitrogen gas will be contained in a 2
How many moles of nitrogen gas will be contained in a 2.00-L flask at STP?
# mol = 2.00 L x factor
V = mol
Answer

42. Or divide the volume given by the Molar Volume:
22.4 L/mol
= mol

43. Mole Conversions
Summary

44. 6.02 x 1023 particles
The molar mass
1 mol =
22.4 L at STP
(gases)

45. Mass (g) Mol # of Particles Volume (L) (STP)
Molar Mass
1 mol
1 mol
Molar Mass
6.02 x 1023
1 mol
22.4 L
1 mol
1 mol
6.02 x 1023
1 mol
22.4 L