12
1 Chapter 3 — Molar Mass — Part 1 1 CHAPTER 3 Molecules, Compounds, and Chemical Equations 2 Electrons Gained/Lost 3 "Biological" Periodic Table
1 Chapter 3 — Molar Mass — Part 1
1
CHAPTER 3!
Molecules, Compounds, and Chemical Equations!
2
Electrons Gained/Lost!
3
"Biological" Periodic Table!
2 Chapter 3 — Molar Mass — Part 1
4
Ethanol C2H6O
dimethyl ether C2H6O
Acetic acid C2H4O2
5
CH
H CH
H
OO HN
6
Functional groups: -OH, -O-,-COOH Ethanol C2H5OH dimethyl ether CH3OCH3
Acetic acid CH3COOH
3 Chapter 3 — Molar Mass — Part 1
7
C C OH
H
H
H
H
H
H C O C H
H H
HH
ethanol dimethyl ether
C
H
H
H
C
O
OH
acetic acid
8
Molecular Formula!
Empirical Formula! "Multiplier"!
C2H4O2! CH2O! 2!
C6H6! CH! 6!
C2H6O! C2H6O! 1!
S8! S! 8!
9
4 Chapter 3 — Molar Mass — Part 1
10
11
12
5 Chapter 3 — Molar Mass — Part 1
13
14
15
Moles Mass divide by molar mass
x molar mass
Moles Mass divide by molar mass
x molar mass Number of
Atoms/Molecules x NA
divide by NA
6 Chapter 3 — Molar Mass — Part 1
16
0.200 g • 1 mol24.31 g
= 8.23 x 10-3 mol
8.23 x 10-3 mol • 6.022 x 1023 atoms1 mol
How many atoms in this piece of Mg?
17
18
7 Chapter 3 — Molar Mass — Part 1
19
21.3 g • 1 mol46.08 g
= 0.462 mol
20
We know there are 0.462 mol of C2H6O.!
0.462 mol • 6.022 x 1023 molecules1 mol
21
There are 2.78 x 1023 molecules.!Each molecule contains 2 C atoms.!Therefore, the number of C atoms is!
2.78 x 1023 molecules • 2 C atoms1 molecule
8 Chapter 3 — Molar Mass — Part 1
22
23
Wt. % O = 2 (16 .0 g O per mole )46 .0 g
x 100 % = 69 .6%
Wt. % N = 14.0 g N46.0 g NO2
• 100% = 30.4 %
24
9 Chapter 3 — Molar Mass — Part 1
25
26
53.3 g/mol26.66 g/unit of B2H5
= 2 units of B2H51 mol
27
10 Chapter 3 — Molar Mass — Part 1
28
29
30
Demo of conservation of matter, See Screen 4.3.
11 Chapter 3 — Molar Mass — Part 1
31
32
2! 3! 1!
33
1 5
3 4
1 11/2
2 5
12 Chapter 3 — Molar Mass — Part 1
34
8 1
8 12 11
35
1! 2! 2!
4! 3! 2!
4! 1!1! 2!
