Acids, Bases, and Salts
(Unit Two, Lesson 2.8)
By Margielene D. Judan
Lesson Outline:
Acids vs. Bases Comparison
Neutralization reaction
pH scale
Salts
Acids, bases,
and salts are
evident in the
quality of
environment.
Acids vs. Bases
When dissolved in water, When dissolved in water,
acids: bases:
1. Conduct electricity 1. Conduct electricity
2. Change blue litmus to red 2. Change red litmus to blue
3. Have a sour taste 3. Have a slippery feeling
4. React with bases to 4. React with acids to
neutralize their properties neutralize their properties
5. pH < 7 5. pH > 7
6. React with active metals
to liberate hydrogen
Acids vs. Bases
Most acids have a suffix –ic Bases have hydroxide
attached attached at the end
Examples: Examples:
Sulfuric acid Sodium hydroxide
Nitric acid Calcium hydroxide
Acetic acid (vinegar) Magnesium hydroxide
Acids vs. Bases
Acids have H+ ions at the beginning of their Bases have
formula hydroxide OH-
Examples: ions the end of
their formula
H2CO3
Examples:
HCOOH
NaOH
HCl
Ca(OH)2
Exceptions are the hydrocarbons (they
have C and H in the beginning and a Mg(OH)2
carboxylic acid at the ending [HCOOH])
like CH3COOH, CH3CHOHHCOOH
Hydrocarbon methane carboxylic acid
Acids in the body
Acids are
important even
in your body.
Acids in the body
Acid can be
found in your
teeth. They are
produced by
bacteria. So
always brush
your teeth.
Acids in the body
Acid can also
be found in
your stomach.
Hydrochloric
acid helps
digest food.
Acids in the body
Hydrochloric
acid in your
stomach is ten
times stronger
than carbonic
acid found in
soft drinks.
Acids in the body
Acids, in the
form of sweat
helps also
regulate body
temperature. The
bad odor is
caused by the
bacteria.
Acids in the industry
Acids are also
important in the
industries.
Acids in the industry
Sulfuric acid – manufacture of plastics, detergents,
batteries, and metals
Nitric acid – manufacture of explosives, rubber, dyes,
and pharmaceuticals
Phosphoric acid – manufacture of fertilizers, animal
feeds, detergents, and ceramics
Acetic acid – manufacture of plastic and food
supplements, found in vinegar
Kinds of Acids
Binary or simple acids – contains two
different elements, hydrogen and a
nonmetal (ex. HCl)
Oxyacids – contains oxygen (ex. HNO3)
NEUTRALIZATION
Process of reacting an
acid and base
They combine to form
1. Water
2. Salts
pH SCALE
pH - a measure of H+
concentration in a
solution
Acid < 7
Base > 7
Neutral (pure H2O) = 7
SALTS
Compound produced by neutralization
reaction
Provide essential ions for the body
Ex. NaCl (salt), Potash (K2CO3), Chalk
(CaCO3)
Question:
Will
the pH increase or decrease if NaCl
(table salt) is added to pure water (H2O)?
NaCl + H2O →
Answer:
Nothing will happen. Remember that salt
added to water are products of a
neutralization reaction.
NaCl + H2O → NaOH + HCl
base + acid = water and salt
Recitation: Classify as acid or base
1. HCOOH
2. CH3COOH
3. pH of 8
4. KOH
5. pH of 1
Answers:
1. HCOOH Acid (with H at the beginning)
2. CH3COOH Acid (with hydrocarbon CH3)
3. pH of 8 Base (pH > 7)
4. KOH Base (with OH at the ending)
5. pH of 1 Acid (pH < 7)
Activity: (1/4 sheet of paper)
Write A if it is an acid, B if it is a
base, and N if neither.
1. HCl 6. pH of 7.5
2. pH of 13 7. MgO
3. NaCl 8. C5H9O5COOH
4. Mg(OH)2 9. Ca(OH)2
5. H2O 10. pH of 7
Answers:
1. HCl Acid (with H at the beginning)
2. pH of 13 Base (pH > 7)
3. NaCl Neither (it’s a salt)
4. Mg(OH)2 Base (with OH at the ending)
5. H2 O Neither (pH =7)
6. pH of 7.5 Base (pH > 7)
7. MgO Neither (it’s a salt)
8. C5H9O5COOH Acid (with hydrocarbon and carboxylic acid COOH)
9. Ca(OH)2 Base (with OH at the ending)
10. pH of 7 Neither (pH =7; water)
Quiz tomorrow:
Memorize the p block elements. (15 items)
Long Quiz next, next meeting:
Coverage: pp. 58 – 74 (Lessons 2.5 – 2.8)
Day One (w/ periodic table)
Know how to classify acids, bases and salts based on pH, chemical names and other
properties
Know the properties of colloids
Distinguish solution, suspension and colloid
Know how to locate the elements by groups and periods
Know how to classify elements as metals, metalloids, or nonmetals; solid, liquid or gas
Differentiate elements and compounds
Review the p. 80 Check Your Understanding B.
Day Three (no periodic table)
Memorize all the names of the elements (s, p, d, and f) = 30 items
Sources:
Science Links 7
