1. I. Converting between Particles and Moles II
I. Converting between Particles and Moles II. Converting Between Mass and Moles
The Mole

2. B . Converting Moles to Particles
Suppose you want to determine how many particles of sucrose are in 3.50 moles of sucrose. You know that one mole contains 6.02 x 1023 representative particles.
Therefore, you can write a conversion factor, Avogadro’s number, that relates representative particles to moles of a substance.

3. B. Converting Moles to Particles
You can find the number of representative particles in a number of moles just as you can find the number of roses in 3.5 dozen.
For sucrose, the representative particle is a molecule, so the number of molecules of sucrose is obtained by multiplying 3.50 moles of sucrose by the conversion factor, Avogadro’s number.

4. There are 2.11 x 1024 molecules of sucrose in 3.50 moles.
B. Converting Moles to Particles
There are 2.11 x 1024 molecules of sucrose in 3.50 moles.

5. You can use the inverse of Avogadro’s number as a conversion factor.
B. Converting Particles to Moles
Now, suppose you want to find out how many moles are represented by a certain number of representative particles.
You can use the inverse of Avogadro’s number as a conversion factor.

6. B. Converting Particles to Moles
Example:
Zinc is used as a corrosion-resistant coating on iron and steel. It is also an essential trace element in your diet.
Calculate the number of moles that contain 4.50 x 1024 atoms of zinc (Zn).

7. B. Converting Particles to Moles
Multiply the number of zinc atoms by the conversion factor that is the inverse of Avogadro’s number.
1 mole Zn =
4.50x1024 atoms Zn X
6.02x1023 atoms Zn =
7.48 mol Zn

8. Calculate the number of molecules in 15.7 mol carbon dioxide.
Question 1
Calculate the number of molecules in 15.7 mol carbon dioxide.
Answer
9.45 x 1024 molecules of CO2

9. Calculate the number of moles in 9.22 x 1023 atom iron.
Question 2
Calculate the number of moles in 9.22 x 1023 atom iron.
Answer
1.53 mol Fe

10. A roll of copper wire has a mass of 848 g.
A. Converting Mass to Moles
A roll of copper wire has a mass of 848 g.
How many moles of copper are in the roll?
Use the atomic mass of copper given on the periodic table to apply a conversion factor to the mass given in the problem.

11. A. Converting Mass to Moles
1 mole Cu
848 g Cu X
13.4 mol Cu =
63.5 g Cu

12. Calculate the mass of 0.625 moles of calcium.
B. Converting Moles to Mass
Calculate the mass of moles of calcium.
Use the molar mass of calcium to apply a conversion factor to the number of moles given in the problem.

13. B. Converting Moles to Mass
According to the periodic table, the atomic mass of calcium is amu, so the molar mass of calcium is 40.1g/mole.

14. B. Converting Moles to Mass
0.625 mol Ca X
40.1 g Ca
25.1 g Ca =
1 mol Ca

15. Calculate the mass of 6.89 mol antimony.
Question 3
Calculate the mass of 6.89 mol antimony.
Answer
839g Sb

16. Question 4
A chemist needs mol selenium for a reaction. What mass of selenium should the chemist use?
Answer
5.53g Se

17. Calculate the number of moles in 17.2 g of benzene (C6H6).
Question 5
Calculate the number of moles in 17.2 g of benzene (C6H6).
Answer
0.220 mol C6H6

18. C. Converting Mass to Number of Particles
According to data from the periodic table, the molar mass of lead is g/mol. Apply a conversion factor to convert mass to moles.
1 mole Pb
4.77 g Pb X
207.2 g Pb