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Acids in your life
Acids and Bases
16.1
Acid Properties
 Sour
to metals
 Electrolytes
 React
with litmus (red) and indicators
bases
 H+ ions!!
 Neutralize
Arrhenius Definition
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Bitter
Eat through organic material
 Electrolytes
 React with litmus paper (blue) and indicators
 Neutralize acids
 OH- ions!!
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 Corrosive
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Base Properties
First person to have some understanding of
acids and bases was Svante Arrhenius
Acids – produce hydrogen ions in aqueous
solutions.
Bases – produce hydroxide ions in aqueous
solutions.

Arrhenius Definition
H O
HCl(g)
H+(aq) + Cl-(aq)
H O
NaOH(s)
Na+(aq) + OH-(aq)
H O
HNO3
HC2H3O2 H O
H O
KOH
2
2
2
2
2
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Arrhenius Definition
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This theory was a major step forward – but
somewhat limited.
There is only one kind of base in this theory.
Brønsted Lowry definition
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Acid – hydrogen ion (proton) donor
Base – hydrogen ion (proton) acceptor
HA(g) + H2O(l)  H3O+(aq) + A-(aq)
acid
base
Brønsted Lowry definition
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This broadens the definition
Does not need to be in water
Bases don’t need to contain an OHAll acids/bases in the Arrhenius definition are
also acids/bases in the Brønsted/Lowry
definition.
Brønsted Lowry definition
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Brønsted Lowry
NH4+ (aq) + OH-(aq)
conjugate
conjugate
acid
base
Conjugate acid – the particle formed when a base
gains an H+ ion.
NH3(aq) + H2O(l)
Base
acid
Brønsted Lowry
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Conjugate base – the particle that remains after the
acid donates an H+ ion.
HA(aq) + H2O(l)  H3O+(aq) + AIn this equation HA, (general formula for acids)
donates the proton to the water and water
accepts it.
What is the name of H3O+?
Hydronium ion.
HA is acid. (HCl, HNO3, H2SO4, etc)
Water is the base.

An acid does not react with it’s conjugate base.
It produces a conjugate base.
A conjugate acid-base pair consists of two
substances related by the loss or gain of a single
hydrogen ion.
How can water attract an extra H?
Has 2 lone pair electrons to attract the H+
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Example
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Which of the following represent conjugate
acid-base pairs?
A) HClO4, ClO4B) HCl, ClOC) H2PO4-, HPO42D) HNO3, NO3A, C, and D
B. Acid Strength

Strong acid – completely ionized or completely
dissociated
•
Weak acid – most of the acid molecules remain intact
B. Acid Strength

Common strong acids are
B. Acid Strength
– Sulfuric acid, H2SO4
– Hydrochloric acid, HCl
– Nitric acid, HNO3
– Perchloric acid, HClO4
– Hydrobromic acid, HBr
– Hydroiodic acid, HI
C. Water as an Acid and a Base
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Water is amphoteric – it can behave as either an
acid or as a base
Ionization of water
– Concentration of hydronium and hydroxide are equal
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