Chapter 14: Acids and Bases
Common Acids
Lactic Acid—milk
Acetic Acid-vinegar
Phosphoric Acid-tart flavor in carbonated
beverages
Citric Acid-lemons, oranges, grapefruit
Malic acid- apples
Tartaric acid-grape juice
Common Bases
Household ammonia
Sodium hydroxide-lye
Magnesium hydroxide-milk of magnesia
Aluminum hydroxide-antacid
Sodium hydrogen cabonate-baking soda
Acid Properties
1. Aqueous solutions of acids have a sour
taste.
2. Acids change the color of acid-base
indicators.
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3. Some acids react with active metals
and release hydrogen gas, H2.
4. Acids react with bases to produce salts
in water. (neutralized)
5. Acids conduct electric current.
Acid Nomenclature
Binary acid—an acid that contains only two
different elements
Hydrogen and one more electronegative
element
Binary Acid Nomenclature
1. The name of a binary acid begins with the
prefix hydro-.
2. The root of the name of the second
element follows this prefix.
3. The name ends with the suffix –ic.
Oxyacid-an acid that is a compound of
hydrogen, oxygen, and a third element, usually
a nonmetal.
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Names of oxyacids are based on the anion
name.
No hydro in these names
Some Common Industrial Acids
Sulfuric Acid
Most commonly produced industrial
chemical
More than 47 million tons are made per
year in US alone
Attracts water so is a good dehydrating
agent
Removes water from gases
Removes water from sugar and other
organic compounds
Nitric Acid
Pure is volatile and unstable
Dissolving in water makes more stable
Stains proteins yellow
Suffocating odor
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Phosphoric Acid
Used mainly in fertilizers and animal feeds
Dilute has a sour taste
Flavoring agent in beverages
Cleaning agent in dairy equipment
Also making detergents and ceramics
Hydrochloric Acid
Stomach acid
“pickling” iron and steel
industrial cleaning agent
concentrated is commonly called muriatic
acid—used to clean masonry and maintain
swimming pools
Acetic Acid
Pure is called glacial acetic acid
Freezing point of 17 degrees Celsius
Making plastics
Food supplements
Fungicide
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Bases Properties
1. Aqueous solutions of bases taste bitter.
2. Bases change the color of acid-base
indicators.
3. Dilute aqueous solutions of bases feel
slippery.
4. Bases react with acids to produce salts
and water.
5. Bases conduct electric current.
Arrhenius Acids and Bases
Arrhenius acids—compound that increases
the concentration of hydrogen ions, H+, in
aqueous solution.
Arrhenius base—compound that increases
the concentration of hydroxide ions, OH-, in
aqueous solution
Aqueous Solutions of Acids
Water solutions of Arrhenius acids are
called aqueous acids
All are electrolytes
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Hydrogen ion represented as hydronium
ion H3O+
HNO3 (l) + H2O (l)
H3O+ (aq) + NO3- (aq)
Strength of Acids
Strong acid ionizes completely in aqueous
solution
Weak acid releases few hydrogen ions in
aqueous solution
Aqueous Solutions of Bases
Metal with an OH group
Dissolves in water completely
Some bases produce an OH group when
they react with water
Strength of Bases
Depends on the amount that the base
dissociates
Strong bases are strong electrolytes
Section 2:Acid-Base Theories
Arrhenius definition of acids and bases works
most times
Bronsted-Lowry Acids and Bases
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1923-Danish-chemist-J.N. Bronsted and
English chemist –T. M. Lowry independently
Bronsted-Lowry Acids-molecule or ion that is
a proton donor
All acids donate protons to water
Bronsted-Lowry base- molecule or ion that is
a proton acceptor
Bronsted-Lowry acid-base reaction—
protons are transferred from one reactant to
another
Monoprotic Acid—Acid that can donate only
one proton per molecule
Perchloric acid—HClO4
Hydrochloric Acid—HCl
Nitiric Acid—HNO3
Polyprotic Acid—acid that can donate more
than one proton per molecule
Sulfuric Acid—H2SO4
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Phosphoric Acid-H2PO4
Lose protons one at a time
Diprotic Acid—acid that has 2 protons to
donate
H2SO4 + H2O
H3O+ + HSO4HSO4- + H2O
H3O+ + SO42Triprotic Acid—acid that has 3 protons to
donate
H3PO4 + H2O
H3O+ + H2PO4H2PO4- + H2O
H3O+ + HPO4 2HPO4 2- +H2O
H3O+ + PO4 3Lewis Acids—an atom, ion, or molecule that
accepts an electron pair to form a covalent
bond
Broadest of three definition
Applies of anything with an electron
Formula need not include hydrogen
Need to do Lewis Dot Structures to see
these
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Do NOT have to be aqueous solutions can
be in any phase
Lewis Base—atom, ion, or molecule that
donates an electron pair to form a
covalent bond
Lewis acid-base reactions—formation of
one or more covalent bonds between an
electron-pair and an electron-pair
acceptor
Section 3: Acid-Base Reactions
Conjugate Base—species that remains
after a Bronsted-Lowry acid has given up
a proton is the conjugate base of that
acid
HF + H2O
F- + H3O+
Acid
Conjugate base
The species that is formed when a
Bronsted-Lowry base gains a proton is the
conjugate acid of that base
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HF + H2O
Base
HF + H2O
Acid 1 base 2
F- + H3O+
Conjugate acid
F- + H3O+
base 1 acid 2
Strength of Conjugate Acids and Bases
Hydrochloric acid is a strong acid
Gives up protons readily
Cl- ion has little tendency to attract a
proton
The stronger an acid the weaker its
conjugate base
The stronger a base the weaker its
conjugate acid
HClO4 + H2O
H3O+ + ClO4Stronger acid stronger base
Weaker acid
weaker base
Proton transfer reactions favor the
production of the weaker acid and the
weaker base
See table page 485
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Amphoteric Compounds
Any species that can react as either an
acid of a base is described as amphoteric.
Water is an amphoteric compound
-OH in a molecule
molecules with an –OH can be amphoteric
to be acidic water must attract hydrogen
from a hydroxyl group
works better the more polar the –OH
increase polarity increase acidity
the compound is affected by the number
of oxygen atoms connecter to the –OH
larger number of oxygen the more acidic
Basic Cr(OH)2
Amphoteric Cr(OH)3
Acidic H2CrO4
Neutralization Reactions
Baking soda = sodium bicarbonate and
tartaric acid
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Escaping CO2 causes food to rise
Also antacids for stomach
Strong Acid-Strong Base Neutralization
HCl + NaOH
NaCl + H2O
NaOH
Na+ + OH-
HCl + H2O
H3O+ + ClOverall ion equation
H3O+ +Cl- + Na+ + OH- Na+ +Cl- + 2H2O
Net ionic equation
H3O+ + OH2H2O
Neutralization is the reaction of
hydronium ions and hydroxide ions to form
water molecules
Salt—ionic compound composed of a cation
from a base and an anion for an acid
Neutralizations result in water and salt
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Acid Rain
NO, NO2, CO2, SO2 and SO3 produced in
many industrial processes
Mix with water to form acids
Rainwater is slightly acidic
Can be very acidic—acid rain
Causes damage to statues and ecosystem
1970 acid rain is causing fish populations
to drop
Clean Air Act of 1990—limit set on amount
of SO2 that power plants are permitted to
emit
Has decrease the amount of acid rain
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