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Slides: 10
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Lesson 1 Presentation\Module 10 Lesson 1 Notes 1A.ppt
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Acid/base Theories and
Naming
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Slide 1
Notes:
Acid/base Theories and Naming
Today you are going to view a presentation on
Acids and Bases. We will cover the properties,
three theories and how to name an acid and a
base.
Duration: 00:00:11
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Acid/base Theories and
Naming
Slide 2
Properties
Duration: 00:01:23
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Properties
Acids
 Hydrogen (H+) or
hydronium (H3O+)
 Sour
 Sting
 Weak to strong
electrolytes
 Reacts with metals to
form H2(g)
 Litmus – red
phenolphthalein –
clear
 Less than 7
Notes:
Bases
Ion
Taste
Touch
Solution
Reactive
Indicator
pH
 Hydroxide ion (OH-)
 Bitter
 Slippery, slimy
 Weak to strong
electrolytes
 No reaction with
metals
 Litmus – blue
phenolphthalein –
pink
 Greater than 7
Lets get started by discussing various properties
of acids and bases. To be an acid you will
produce a hydrogen or hydronium ion when
broken down. This also means you must have a
hydrogen to be considered an acid. Acids taste
very sour, they will produce an electric current in
water, react with metals to form the diatomic
molecule hydrogen, if placed in red litmus paper
the paper will stay red. It will turn blue litmus
paper red , when drops of acids are added to
phenolphthalein it will turn stay clear. On a pH
scale, all acids are less than 7; the farther away
from 7 it is, the stronger it is.
-
Bases will produce an OH ion when broken
down. They taste bitter and are extremely
slippery and slimy feeling. They, too, produce
electrolytes when they come in contact with
water. Bases do not react with metals and they
have a pH greater than 7. The farther away from
7 a base is, the stronger it is. Bases turn litmus
paper B (just remember B for bases) and when
placed in phenolphthalein it will turn pinkish in
color.
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Slide 3
Arrhenius Theory
Arrhenius Theory
Duration: 00:00:32
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 Produce OH- in solution
 Group IA and IIA metals react with
water to produce bases
Acids
• Produce H+ in solution
 2Na + 2H2O  2NaOH + H2
• Ionizable hydrogens: H in a
polar covalent bond that can  Some are very soluble
 NaOH, KOH, LiOH, Sr(OH)2
be ionized in solution –
are slightly soluble
generally at front of formula  Some
 Be(OH) , Ca(OH) , Mg(OH)
– Monoprotic: HCl, HF, HNO3,
HC2H3O2
– Diprotic: H2SO4, H2CO3
– Triprotic: H3PO4
• HCl  H+ + Cl•
•
Slide 4
Notes:
Bases
Many foods and beverages we
consume are acidic
HCl in our stomach
2
2
-
2
 Because of low solubility, Mg(OH)2
is used in antacids to neutralize
excess stomach acid, ease
heartburn
 Used to clean drains (Drano, etc),
in soaps, other cleaners
 Caustic: cause deep, painful,
slow-healing wounds
(wash off immediately)
Bronsted-Lowry Theory
• Acids – H+ donor
• Bases – H+ acceptor
• So, substances excluded
from Arrhenius Theory
can be bases
• NH3 + H2O  NH4+ + OH• Na2CO3 + H2O  HCO3- + OH+ 2Na+
• Conjugate acid-base pairs
• When an acid donates a
proton, the species left is
called a conjugate base
• When a base accepts a
proton, the species left is a
conjugate acid
NH3 + H2O  NH4+ + OHes
a
b
Slide 5
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Conjugate Acid-Base Pairs
Conjugate Acid-Base Pairs
Duration: 00:00:20
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Substances that
can act as an
acid or a base
are called
amphoteric.
Any substance
that has an
ionizable
hydrogen AND
a negative
charge is also
amphoteric.
Acid
Base
HCl
Cl-
H2SO4
HSO4-
H3O+
H2O
HSO4-
SO4-2
CH3COOH/HC2H3O2
CH3COO-/C2H3O2-
H2CO3
HCO3-
HCO3-
CO3-2
HF
F-
NH4+
NH3
H2O
OH-
HNO3
NO3-
H3PO4
H2PO4-
and OH in water. Hydrogen is usually the first
element listed in the compound while hydroxide
is found at the end of a basic compound. The
problem observed in the Arrhenius Theory is not
all acids break down to give you that hydronium
ion and not all bases have the hydroxide ion.
Notes:
Bronsted-Lowry Theory
Duration: 00:00:40
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There are various theories when discussing
acids and bases. The first one we are going to
discuss is the Arrhenius Theory. Arrhenius
+
Theory focuses on acids producing H in water
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Bronsted-Lowry Theory is the theory that is
considered to be more complete as it focuses on
which compounds donates the hydrogen and the
compound that accepts that hydrogen. This
allows substances excluded from the Arrhenius
Theory to be considered a base. One additional
item of consideration for the Bronsted-Lowry
theory is the conjugate acid/base pairs. When
an acid donates a hydrogen (often referred to as
a proton), that which is left is called a conjugate
base. When a base accepts a proton, that which
is left is referred to as a conjugate acid.
Notes:
Substances that act as an acid or base are
called amphoteric. Any substance that has an
ionizable hydrogen AND a negative charge is
also called amphoteric. This chart provides
examples of conjugate acids and bases based
off the losing of a hydrogen.
H3O+  H2O  OH-
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Slide 6
Lewis Theory
Lewis Theory
Duration: 00:00:28
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•
•
•
More general than the other two theories
Acids are electron pair acceptors
– H+ can form a covalent bond with a pair of eBases are electron pair donors
– OH- can form a covalent bond using a pair of e-
Type
Acid
Base
Arrhenius
H+ producer
OH- producer
BrØnsted-Lowry
H+ donor
H+ acceptor
Lewis
Electron-pair acceptor
Electron-pair donor
Slide 7
Strength of Acids and Bases
Strength of Acids and Bases
Duration: 00:00:20
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•
•
•
•
•
Strength is very different than concentration
When molecular substances dissolve, the molecules stay intact
Acids are different because some of the molecules “break up”, or ionize
The degree to which the molecules ionize is the “strength” of the acid
A strong acid is one that completely (100%) ionize in solution
Slide 8
Strong Acids/Bases
Strong Acids/Bases
Duration: 00:00:13
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• Strong
–
–
–
–
–
–
HCl hydrochloric acid
HBr hydrobromic acid
HI hydroiodic acid
H2SO4 sulfuric acid
HNO3 nitric acid
HClO4 perchloric acid
• All others are Weak
– H3PO4 phosphoric acid
– HC2H3O2 acetic (ethanoic)
acid
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• Strong
– All group IA and IIA
hydroxides, such as
– NaOH sodium hydroxide
– KOH potassium hydroxide
– Ca(OH)2 calcium hydroxide
– Many of these are only
slightly soluble, but what
does dissolve, ionizes
completely
Notes:
The third theory one must consider is the Lewis
theory. As one might expect, the Lewis theory
focuses on electrons. The Lewis Theory is the
most general of the three. Acids are defined as
the elements/compounds that accept electron
pairs. Bases are defined as those which donate
electron pairs.
The chart included on this slide breaks down and
compares all three theories we have discussed
in this presentation.
Notes:
The strength of acids and bases is different than
concentration. When molecular substances
dissolve the molecules stay intact. The degree
to which the substances dissolve defines the
strength of the acid or base. A strong acid is one
that completely ionizes in solution.
Notes:
This slide provides you examples of strong acids
and bases. Recall that the degree of strength
comes down to the level with which they
dissolve/break apart in solution.
• All others are Weak
– NH3 ammonia
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Slide 9
Notes:
Naming Binary Acids
Finally in this presentation we are going to
discuss how acids and bases are named. To
name a base you will just name according to the
ionic and covalent bonding rules. Acids are a
little more complicated than that and therefore
have their own set of rules. When naming a
binary acid (that is an acid with two compounds),
you will make sure it begins with hydro. Keep
the root name of the non-metal but instead of
turning the ending to “ide” you will place “ic” for
the ending and then conclude the name with
acid. Examples have been included to show
you these rules in action.
Duration: 00:00:43
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Slide 10
Ternary Acids
Ternary Acids
Duration: 00:00:59
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•
•
•
•
H + polyatomic ion
Begin with polyatomic ion without the ending
Add suffix “ic” if there was an “-ate” ending
Add suffix “ous” if there was an “ite” ending
•
HNO3 NO3 is the polyatomic ion for nitrate; adding the hydrogen means
you name it nitric acid.
H3PO4 PO4 is the polyatomic ion for phosphate; adding the hydrogen
means you name it phosphoric acid
•
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Notes:
A ternary acid is one that includes a polyatomic
ion and hydrogen. To name these classes of
elements you will begin with the polyatomic ion
minus the ending (that is the ate or ite ending). If
the polyatomic ion ends in “ate” then you will
need to add “ic” to the ending and include the
name acid to complete the acid’s name. If the
polyatomic ion ends in “ite” then you will turn the
ending to “ous” and again, make sure you
conclude the compound name with the word
acid. Examples of both types of naming have
been included on this slide. Make sure you keep
a polyatomic ion list handy and this will help you
a great deal.
In this presentation we have covered the basics
of acid/base theory as well as properties and
how to name. Make sure to watch the videos
included in the notes section to help you further
build you acid and base knowledge.
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