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 7 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. 6.02 X 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.

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

9. There are 7 diatomic elements:
Memory trick: HBrONClIF or 7th Heaven

10. 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.

11. 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.

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

13. 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

14. How many moles are 1.20 x 1025 atoms of phosphorous?

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 atoms are in 0.750 mol of Zn?

17. 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

18. How many molecules are in 0.400 mol N2O5?

19. 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

20. How many moles are contained in 1.20 x 1024 molecules CO2?

21. Gram atomic mass (gam) -atomic mass of an element in grams -mass of one mole of atoms of a monatomic element -use the periodic table and take masses to 0.1 g

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

23. There are two terms to describe the mass of a chemical compound; gram molecular mass and gram formula mass.
We will most often use the term gram formula mass. Molar mass of molecular weight are terms also used to mean the same thing.

24. Gram molecular mass (gmm) -mass of one mole of any molecule -sum of the atomic masses of each atom in the molecule
1 mol H2O: 2 mol H mol O =2 mol H x 1.0 g H/mol = g =1 mol O x 16.0 g O/mol= g g H2O

25. What is the gram molecular mass of CH3OH?
C 1 x = 12.0
H 4 x = 4.0
O 1 x = 16.0
32.0 g

26. What is the gram molecular mass of CH3OH?

27. Gram formula mass (gfm) -mass of one mole of an ionic compound -sum of the atomic masses of each atom in a formula unit

28. What is the gfm of magnesium phosphate?
Mg3(PO4)2
3 mol Mg 3 x 24.3 g = g
2 mol P x 31.0 g = g
8 mol O x 16.0 g =128.0 g
262.9 g

29. What is the gfm of magnesium phosphate?

30. What is the molar mass of ammonium sulfate?
(NH4)2SO4
2 mol N 2 x 14.0 = 28.0
8 mol H 8 x = 8.0
1 mol S 1 x = 32.1
4 mol O 4 x = 64.0
132.1 g

31. What is the molar mass of ammonium sulfate?