Chemistry 1

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Chemistry 1
Chapter 18 Acids and Bases
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Chapter 18 Objectives
I. Compare and Contrast the Bronsted-Lowry and
Arrhenias definitions of acids and bases.
II. Use the proton donor/acceptor concept to
identify conjugate acid base pairs.
III. Identify the common physical and chemical
properties of acids and bases and know how
indicators are used to identify them.
IV. Write the expression for the acid/base
dissociation constant and use the data to
calculate the dissipation constant.
V. Explain how the dissociation constant can be
used to compare the relative strengths of acids
and bases.
VI. Describe a salt hydrolysis reaction and
identify the result as acidic basic or neutral.
VII. Know types of acids and bases, be able to
name them using correct nomenclature.
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Acids
Arrhenius Substances that dissociate in water to
make H or (H3O) ions.
Bronsted-Lowry Proton Donor
Are Corrosive
Facts 1. Acids are strong when they dissociate
in water (most of the acid breaks up) 2. Acids
are weak when they DONT dissociate in water
(only small amounts of the acid actually breaks
up) 3. The stronger the acid, the weaker the
conjugate base. 4. The weaker the acid, the
stronger the conjugate base.
Have pH of less than 7
Larger the Ka Stronger Acid
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Bases
Arrhenius Substances that dissociate in water to
make OH- ions
Bronsted-Lowry Proton Acceptor
FOUR STRONG BASES Calcium Oxide (CaO) Sodium
Hydroxide (NaOH) Potassium Hydroxide (KOH)
Calcium Hydroxide(Ca(OH)2)
Have pH of greater than 7
Feel Slippery or Slimy
Are Caustic
A strong base is a base which hydrolyzes
completely, raising the pH of the solution
towards 14
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Together acids and bases for neutralization
reactions
The pH of a solution is a measurement of the
concentration of hydronium. This will depend on
the concentration and nature of acids and bases
in solution.
The strength of an acid is measured by its acid
dissociation constant (Ka)
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Buffer Resists change in pH Weak acid
conjugate base
Both are usually on the reactant side of the
equation
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Acidic
Neutral
Basic
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The name of the Acid typically comes from the
anion it produces when it dissociates.
Three Rules for naming Acids If the anion ends in
-ide, the name of the acid that produces it
includes the name of the anion hydro___ic
acid If the anion has no prefix and ends in -ate,
the name of the acid that produces this ion ends
in -ic ___ ic acid If the anion ends in -ite,
the acid that produces it has no prefix and ends
in -ous ___ ous acid
Naming Acids
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The Acid Dissociation Constant
The acid dissociation constant, Ka is a measure
of the strength of an acid.
Call a weak acid HA, H is a Hydrogen molecule and
A is the rest of the acid molecule. Because HA is
weak it only partially dissociates in water.
Equilibrium constant is to Keq
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The Acid Dissociation Constant
Keq and H2O equals a constant, which is called
the acid dissociation constant or Ka
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Salt Hydrolysis Reactions
The reactants of ions from salts to form H3O or
OH-
When dissolved in water they dissociate into
anions and cations
Salts are strong electrolytes
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Review Quiz
A) Substances that dissociate in water to make
OH- ions B) Substances that dissociate in water
to make H or (H3O) ions. C) Proton Donors D)
Proton Acceptors
A) Substances that dissociate in water to make
OH- ions B) Substances that dissociate in water
to make H or (H3O) ions. C) Proton Donors D)
Proton Acceptors
According to Arrhenius, Acids are
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Review Quiz
Identify the conjugate pairs
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Review Quiz
A) Caustic B) Corrosive
A) Caustic B) Corrosive
Bases are
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Review Quiz
The acid dissociation constant that measures the
strength of an acid is represented by
A) Keq B) Ksp C) Ka D Kb
A) Keq B) Ksp C) Ka D Kb
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Review Quiz
A) Highly Basic B) Highly Acidic C) Neutral D)
Slightly Acidic
A) Highly Basic B) Highly Acidic C) Neutral D)
Slightly Acidic
If the acid in a salt is stronger than the base
then the salt is
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Review Quiz
If naming an acid with a Hydrogen and a nitrate
(NO3-) ion, what would you call it?
A) Nitrous Acid B) Nitric Acid C) Hydronitric Acid
A) Nitrous Acid B) Nitric Acid C) Hydronitric Acid