Acids Bases

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- Properties
- Arrhenius Acids and Bases
- Naming acids and bases
Mr. Shields
Regents Chemistry
U15 L01
Properties
We’ve all encountered acids
and bases in our Daily lives.
For example all of these
common items are examples
Acids
Of acids or bases
Other examples are:
Acid Rain Tea
Coke
Car batteries
Ants
Antacids
What kind of properties do
These substances exhibit?
Bases
Properties
Acids
Taste Sour
Feel like water
React w/ bases to form
water & salt (neutralization)
React with metals to
produce H2 & salt (Table J)
Good electrolytes

i.e ionizes & conducts
electricity in solution
Acids turn litmus red

What color is the paper?
Phenolphthalein turns
colorless
Bases
Taste Bitter
Feel slippery
React with acids to form
water & salt (neutralization)
Won’t react with metals
Good electrolytes
Bases turn litmus blue

What color is the paper?
Phenolphthalein turns pink
Reaction with Metals
OK. So …What metals will react with acids?
See Table J to figure this out
All the metals above H2 will react with acids.
Cu, Ag, and Au do not react with acids.
Example: 2HCl + Mg  MgCl2 +
(a salt)
H2
Mg is above H2 in Table J so this reaction
proceeds as indicated. What kind of rxn is this?
Single replacement
(why)
Mg replaces H
What kind of rxn is this
Redox (why?)
2H+ +2e-  H20 (red.)
Mg0  Mg+2 +2e- (ox.)
Problem: Will the following reaction proceed as
indicated?
6HCl + 2Au  3H2 + 2AuCl3
No. Gold is below Hydrogen in Table J
Problem: Will the following reaction proceed as
indicated?
6HCl + 2Co  3H2 + 2CoCl3
Yes. Cobalt is above Hydrogen in Table J
Neutralization Reactions
Acid + Base  Salt + Water
A Double Replacement Reaction
HCl + NaOH  NaCl + HOH
This is Not Redox (How do I know?)
What kind of reaction is this?
Neutralization
Acid + Base  Salt + Water
HCl(aq) + NaOH(aq)  NaCl(aq) + H2O(l)
What is the Ionic Equation for the above rxn?
H+(aq) +Cl-(aq) +Na+(aq) +OH-(aq)  H2O(l) +Na+ (aq) + Cl-(aq)
This works because H+ + OH-  H2O (a Molecule)
(one of the ways double replacement goes to completion)
Which ions are the spectator Ions?
Na+ and Cl- are spectator ions
Arrhenius Theory
An early attempt (1884) to explain acids and
bases is known as the Arrhenius Theory.
-This was the first successful definition of
what an acid and base is
-It was based on what ion is released
when the Compound is dissolved in water
Arrhenius Theory
- According to Arrhenius, Acids are
compounds that contain hydrogen and
ionizes in water to yield hydrogen ions (H+)
Examples:
HCl + H2O  H+ (aq) + Cl-(aq)
H2SO4 + H2O  2H+ (aq) + SO42- (aq)
Arrhenius Theory
Take out your Reference Tables. Look at Table K
Table K list the name and formulas of some
common acids.
ALL of these
Acids are
Arrhenius acids.
They all produce
H+ ions in sol’n
Naming Binary Acids
A binary acid is an acid with only 2 elements.
They are named as follows:
Hydro + Stem of nonmetal ion + ic
(ex. Chloride  Chlor)
HF = ?
Hydrofluoric acid
HI = ?
Hydroiodic acid
HCl = ?
Hydrochloric acid
Naming Ternary Acids
A Ternary acid is composed of 3 elements. The
Name is derived from the polyatomic anion (see
Table E)
Replace –ite with –ous plus acid
NO2- is nitrite
HNO2 is nitrous acid
Replace –ate with –ic plus acid
NO3- is nitrate
HNO3 is nitric acid
Ternary Acids
For polyatomics with S and P, the stem
becomes long again.
H3PO4 = phosphoric acid, not phosphic acid
H2SO4 = sulfuric acid, not sulfic acid
H2SO3 = sulfurous acid, not sulfous acid
Kinds of Acids
Acids can produce one or more protons (H+)
When dissolved in water.
-Acids that release one H+ are called
MONOPROTIC
example: HCL + H20  H+ + Cl- Acids that release two H+ are called DIPROTIC
example: H2SO4 + H20  2H+ + SO4-2
Kinds of Acids
- Acids that release three H+ are called TRIPROTIC
example: H3PO4 + H20  3H+ + PO4-3
Notice Table K also lists CH3COOH (acetic acid)
- this is an “organic” acid
- It has only one ionizable H+ (i.e monoprotic)
CH3COOH + H20  CH3COO- + H+
The ion CH3COO- is known as the Acetate Ion
Types of Acids
What are the names of the following acids, what
Kind of acids are they and how many protons are
released when the acid hydolyszed in water?:
HNO3
H3PO4
HNO2
H2SO4
HI
H2CO3
H2SO3
CH3COOH
Arrhenius Base
According to Arrhenius an acid is a
substance that contains hydrogen and
produces H+ in aqueous solutions.

So how did Arrhenius define a base?
A substance that contains hydroxide and
produces OH- as the only negative ion in
aqueous solution.
Arrhenius Bases
According to Arrhenius a base is a compound
That ionizes in water to yield HYDROXIDE (OH-)
Example:
NaOH + H20  Na+ + OH-
Table L list some of the
More common bases.
All of these bases are
Arrhenius bases except
NH3. We’ll discuss NH3
Later.
Naming Bases
Naming hydroxides  metal name + hydroxide
Monohydroxy
NaOH = ?
Dihydroxy
Ca(OH)2 = ?
Mg(OH)2 = ?
Trihydroxy
Fe(OH)3 = ?
Iron (III) Hydroxide!
Problem:
Correctly identify which pair is an Arrhenius acid
and Arrhenius base:
HCl and NaCl
H3PO4 and Ca(OH)2
H2CO3 and CO2
HNO3 and NH3
H3PO4 and Ca(OH)2 are the correct choice
because phosphoric acid donates H+ and
Ca(OH)2 because it donates OH-
Base preparation
Group 1 metals react vigorously with water to
produce hydroxides
Remember the reactions we did in class?
2Li + 2H20  2LiOH + H2
Fast Reactions
2K + 2H20  2KOH + H2
2Na + 2H20  2NaOH + H2
Group 1 hydroxides are VERY SOLUABLE in water
Base preparation
Group 2 metals react less vigorously than
Group 1 metals with water.
Ca + 2H20  Ca(OH)2 + H2
Mg + 2H20  Mg(OH)2 + H2
Group 2 hydroxides are only very slightly soluble in water.
Ca(OH)2 = 0.165g/100ml
Mg(OH)2 = 0.0009g/100ml  Suspended in water this is
known as Milk of Magnesia
Acid/Basic Oxides
Metal and non-metal oxides when dissolved in water form
acids and bases.
Non-metal oxides
produce acids
CO2 + H20 
H2CO3
Metal oxides
produce bases
K20 + H20 
2KOH
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