Download Slides

Chemistry 111
Chapter 16.1-16.6, 16.9
1
Duh…
• I made another mistake,
this time in a key spot…
(but several of you
figured it out!)
• The conversion is upside down:
nb mol   M b 
mol


L
L  Vb L  
 1000 mL 


2
Another Thing…
Deaths at Japan nuclear plant
Monday, August 9, 2004 Posted: 6:17 AM EDT (1017 GMT)
TOKYO, Japan -- A steam leak at a nuclear power plant northwest of Tokyo
has killed four workers and injured at least 10 others, several critically,
Japanese media and officials have reported.
Kyodo News Service and public broadcaster NHK reported that four workers
had died after suffering severe burns, and that at least one other worker was
in critical condition.
Those who died were exposed to steam as hot as
200 Celsius (392 Fahrenheit), officials said. The
accident was described as the worst ever in terms
of deaths at a nuclear facility in Japan.
3
Chapter 16.1 – 16.6, 16.9
•
•
•
•
•
Solutions
Definitions / Terminology
Formation of a Solution
Solubility
Concentrations:
– Percent
– Molarity
– Other
4
Solutions - Definition
“A solution is a homogenous mixture.”
This Morning
This Weekend
What solutions
did you eat:
What solutions
did you use:
5
Solutions - Definitions
• Definitions
–
–
–
–
Solute / Solvent
Concentrated / Dilute
Solubility
Saturated /
Unsaturated /
Supersaturated
– Miscible / Immiscible
– Dissolve / Precipitate
• Example / Notes
___________________
___________________
___________________
___________________
___________________
___________________
___________________
___________________
___________________
___________________
___________________
6
Formation of a Solution
• We will work an extended example with
NaCl (Ionic solution)
– Cartoon of:
• Pure Samples
• Initial dissolution (dissolving)
• Some Precipitation
• Equilibrium
7
Frame 1: No Solution
Dish
Beaker
8
Frame 2: Dropped in the NaCl
9
Frame 2: NaCl Starts to Dissolve
Na+ (aq) + Cl- (aq)
Na+
O
H
NaCl (s)
H
Cl-
10
Frame 3: NaCl Starts to Precipitate
Na+
Na+
Na+ (aq) + Cl- (aq)
Cl-
NaCl (s)
Na+
Cl-
Cl-
11
Frame 4: Solution Reaches Equlibrium
Na+
ClNa+
Cl-
Na+
Cl-
Na+
Cl-
Na+
Cl-
Na+
Na+
Na+
ClNa+
ClNa+
Cl-
(aq)
Cl-
Na+
Cl-
ClNa+
ClNa+
Cl-
Na+
Cl-
Cl-
Na+
ClNa+
Na+
ClNa+
Cl-
Cl-
Na+
(aq) +
Na+
Cl-
Na+
ClNa+
Na+
Na+
Cl-
Na+
Cl-
Cl-
Cl-
Na+
Cl-
NaCl (s)
12
Why Do Things Dissolve?
• To stay dissolved, we have to fight
Density / Gravity
• What holds it together?
– Intermolecular Forces
• Oil + Oil / Oil + Water / Water + Water
Water + Duck’s Back
– Temperature
• Fish bowl in the Window
– Gas Pressure (Open a Soda Can!)
13
Why Do Things Dissolve?
• Intermolecular Forces:
– Oil + Water?
– Water + Alcohol?
– Chili Oil + Water?
– Chili Oil + Oil? (Chinese Hot Oil)
– Water + Duck’s Back?
14
Why do things Dissolve
• Temperature & Gases
15
Concentration
•
•
•
•
Ratios
Units
Making Solutions
Harder Math:
– Dilution
– Titration
– Stoichiometry
Tomorrow
16
Concentration Ratios
• Solutions concentration is a RATIO:
C 
Amount of Solute
Amount of Solvent
or:
C 
Amount of Solute
Amount of Solution
We use the ratio that works best for our
current purposes.
17
Concentration Units
Name
Ratio
Use
Ignore?
Percent (%)
g Solute
100 g Solution
Consumer Products
No
Parts-Per-Million
(ppm)
mg Solute
L Solution
EPA Guidelines
No
Molarity (M)
mol Solute
L Solution
Chemistry
No
Molality (m)
mol Solute
kg Solvent
Industrial
Yes
Normality (N)
mol Equivalents
L Solution
Fading away…
Yes
18
Concentration Example
• Saline Nasal Spray = 0.65% NaCl
– ($3.00 @ Safeway for 1.5 FL OZ / 44 mL)
g Solute
0.65 g Solute
%

100 g Solution 100 g Solution
• How much NaCl to refill the bottle?
1.0 g Soln.  0.65 g NaCl 
  0.286 g NaCl
44 mL Soln. 
 
1.0 ml Soln.  100 g Soln. 
19