Swimming Pool. Review Acids, Bases and Salts HW Vocabulary pH and pOH Calculation pH Practice...
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Transcript of Swimming Pool. Review Acids, Bases and Salts HW Vocabulary pH and pOH Calculation pH Practice...
HCl
H2SO4
H3PO4
HNO3
CH3COOH
HF
Hydrochloric acid
Sulfuric acid
Phosphoric acid
Nitric acid
Acetic acid
Hydrofluoric acid
stomach acid, pickling metal
battery acid, # 1 selling chemical
food flavoring
fertilizer, explosives
vinegar
etch glass
NaOH Ca(OH)2 NH4OH
sodium hydroxide calcium hydroxide ammonium hydroxide
pH scale0
7
14
acid
neutral
base
[H+] = [OH-]
Soren Sorenson developed pH scale
pOH = -log [OH-]
kW = [H+] [OH-]
pH = -log [H+]
pH + pOH = 14
(alkalinity)
Arnold Beckman invented the pH meter
H+ + H2O H3O+
proton hydronium ion
kw = 1 x 10-14
Concentrated vs. Dilute
Concentration: Molarity molality Normality
M = molL m =
molkg
H2SO4 2 H1+ + SO42-
3 M “6 M”
Strong / Weak Acid
Strong HA H+ + A- (~100% dissociation)
Weak HA H+ + A- (~20% dissociation)
Ka = [Product][Reactant]
acid dissociation constant
Ka
0.8 H3PO4 3H+ + PO43-
0.0021 HF H+ + F-
H2A 2 H+ + A-
Ka = [H+]2 [A-]
[H2A]
Acid + Base Salt + Water
How would you make calcium sulfate in the lab?
+ CaSO4
ACID
Sour taste, litmus red
Arrhenius – H+ as only ion in water
Brønsted-Lowry – proton donor
BASE
bitter taste, litmus blue
Arrhenius – OH- as only ion in water
Brønsted-Lowry – proton acceptor
H2SO4 Ca(OH)2 + 2 H2O? ?
phenolphthalein colorless pinkacid baseweak strong
bromthymol blue yellow blue
acid basestrong strong
universal indicator R O Y G B I V
pH 4 7 12
litmus paper & pH paper
Indicators
Buffers - salts of weak acids and weak bases that maintain a pH
LeChatelier’s Principle
- acidosis & alkalosis (bicarbonate ion acts as buffer)- darkening glasses- egg shells thinner in summer (warm)
e.g. Aspirin (acetyl salicylic acid) vs. Bufferinlow pH upsets stomach
Acid – Base Concentrations
pH = 3
pH = 7
pH = 11
OH-
H3O+OH-
OH-H3O+
H3O+
[H3O+] = [OH-] [H3O+] > [OH-] [H3O+] < [OH-]
acidicsolution
neutralsolution
basicsolution
co
nc
en
trat
ion
(m
ole
s/L
)
10-14
10-7
10-1
Timberlake, Chemistry 7th Edition, page 332
Amino Acids – Functional Groups
Amine Carboxylic AcidBase Pair
NH21- R- COOH
NH3NH21- NH4
1+
amine ammonia ammonium ion
NH
HH
:
NH
HH
H : 1+
NH
H
:
1-
:
H+ lose H+
Amino Acids – Functional Groups
Amine Carboxylic AcidBase Pair
NH21- R- COOH
O2-
H+
H+
+
http://fig.cox.miami.edu/~cmallery/150/chemistry/sf3x17b.jpg
Water – Amphiprotic
H2OOH1- H3O1+
hydroxide water hydronium ion
NH
HH
:
NH
HH
H : 1+
NH
H
: 1-
:
H+ lose H+
Water – Also Amphiprotic
H2OOH1- H3O1+
hydroxide water hydronium ion
H+ lose H+
Amphiprotic – Act as an acid (proton donor) or base (proton acceptor)
O2-
H+
H+
+
Amino Acids – Functional Groups
H2OOH1- H3O1+
hydroxide water hydronium ion
H+ lose H+
Amphiprotic – Act as an acid (proton donor) or base (proton acceptor)
O2-
H+
H+
+
http://fig.cox.miami.edu/~cmallery/150/chemistry/sf3x17b.jpg
Range and Color Changes of SomeCommon Acid-Base Indicators
Indicators
pH Scale1 2 3 4 5 6 7 8 9 10 11 12 13 14
Methyl orange red 3.1 – 4.4 yellow
Methyl red red 4.4 6.2 yellow
Bromthymol blue yellow 6.2 7.6 blue
Neutral red red 6.8 8.0 yellow
Phenolphthalein colorless 8.0 10.0 red colorless beyond 13.0
Range and Color Changes of SomeCommon Acid-Base Indicators
Indicators
pH Scale1 2 3 4 5 6 7 8 9 10 11 12 13 14
Methyl orange red 3.1 – 4.4 yellow
Methyl red red 4.4 6.2 yellow
Bromthymol blue yellow 6.2 7.6 blue
Neutral red red 6.8 8.0 yellow
Phenolphthalein colorless 8.0 10.0 red colorless beyond 13.0
pH Paper
pH 0 1 2 3 4 5 6
pH 7 8 9 10 11 12 13
pH Paper
pH 0 1 2 3 4 5 6
pH 7 8 9 10 11 12 13
pH Paper
pH 0 1 2 3 4 5 6
pH 7 8 9 10 11 12 13
pH Paper
pH 0 1 2 3 4 5 6
pH 7 8 9 10 11 12 13
Neutralization of Bug Bites
Wasp - stings with base
(neutralize with lemon juice or vinegar)
Red Ant - bites with acid
(neutralize with baking soda)
StrengthStrength
Strong Acid/BaseStrong Acid/Base• 100% ionized in water• strong electrolyte
- +
HCl
HNO3
H2SO4
HBr
HI
HClO4
NaOH
KOH
Ca(OH)2
Ba(OH)2
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
StrengthStrength
Weak Acid/BaseWeak Acid/Base• does not ionize completely• weak electrolyte
- +
HF
CH3COOH
H3PO4
H2CO3
HCN
NH3
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Ionization of WaterIonization of Water
H2O + H2O H3O+ + OH-
Kw = [H3O+][OH-] = 1.0 10-14
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Why is pure water pH = 7?Why is pure water pH = 7?
1 in 500,000,000 water molecules will autoionize.
H2O + H2O H3O+ + OH1-
This yields a hydronium ion concentration of 1 x 10-7 M H3O+ per liter of solution
pH = -log[H3O+]
pH = -log[1 x 10-7] or pH = 7
HH
OHH
HH
HHO
HH1-
1+
HHO
HH
HH
O HH
HH
OHH
HH O
HH
O
HH
HH
HH
O
HH
Ionization of WaterIonization of Water
Find the hydroxide ion concentration of 3.0 10-2 M HCl.
[H3O+][OH-] = 1.0 10-14
[3.0 10-2][OH-] = 1.0 10-14
[OH-] = 3.3 10-13 M
Acidic or basic?AcidicCourtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
pH = -log[H3O+]
pH ScalepH Scale
0
7INCREASING
ACIDITY NEUTRALINCREASING
BASICITY
14
pouvoir hydrogène (Fr.)“hydrogen power”
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
pH ScalepH Scale
pH = -log[H3O+]
pOH = -log[OH-]
pH + pOH = 14
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
pH ScalepH Scale
What is the pH of 0.050 M HNO3?
pH = -log[H3O+]
pH = -log[0.050]
pH = 1.3
Acidic or basic?Acidic
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
pH ScalepH Scale
What is the molarity of HBr in a solution that has a pOH of 9.6?
pH + pOH = 14
pH + 9.6 = 14
pH = 4.4
Acidic
pH = -log[H3O+]
4.4 = -log[H3O+]
-4.4 = log[H3O+]
[H3O+] = 4.0 10-5 M HBrCourtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Resources - Acids and Bases
Objectives
Worksheet - vocabulary
Worksheet - pH and pOH calculations - pH and pOH calculations
Worksheet - practice problems (key)
Textbook - text ?'s chemical equilibrium
Worksheet - weak acid, pKWorksheet - weak acid, pKaa
Article - aspirinArticle - aspirin
Lab - synthesis of aspirin
Worksheet - aqueous acids and bases titration
Outline ((general)
Video (VHS) - future of the past
Outline - Outline -
Worksheet - Worksheet -
Worksheet - Worksheet -
Worksheet - Worksheet -
Worksheet - Worksheet -
Lab - titrationLab - titration
Textbook - questionsTextbook - questions
Episode 16 – The Proton in Chemistry