Physical Science

1. Acids and Bases
Lesson 1

2. How can you determine whether a solution is
acidic or basic?
Focus Question

3. base
hydroxide ion
indicator
hydronium ion
acid
New Vocabulary

4. electrolyte: compound that breaks apart in
water, forming ions that can conduct electricity
Review Vocabulary

5. • An acid is a substance that produces hydrogen ions (H+)
in a water solution.
• The H+ ions interact with water molecules to produce
hydronium ions: H3O+.
• Acids are corrosive, and many react strongly with metals
such as zinc. Acids cause the sour taste in foods such as
limes and pickles.
• Acids react with indicators. An indicator is an organic
compound that changes color in the presence of acids
and bases. Blue litmus paper turns red in acids.
Acids

6. Name, Formula Use Other Information
Acetic acid (CH3COOH) food preservation,
commercial organic
synthesis
vinegar (about 5% acetic acid)
Ascorbic acid (H2C6H6O6) antioxidant, vitamin Vitamin C; occurs naturally in
some foods and is added to
others
Carbonic acid (H2CO3) carbonated drinks involved in cave formation and
acid rain
Hydrochloric acid (HCl) cleans steel in a process
called pickling
Gastric juice in the stomach is
a solution of HCl and water.
Sulfuric acid (H2SO4) car batteries; to
manufacture fertilizers
and other chemicals
Dehydrating agent that
extracts water from air.
Some Common Acids and Their Uses
Acids

7. • Most bases contain an OH–, called a hydroxide ion, in
their chemical formula.
• A base is a substance that produces hydroxide ions
when it is dissolved in water. Also, a base is any
substance that accepts H+ from acids.
• In their pure state, many bases are crystalline solids. In
solution, bases feel slippery and have a bitter taste. They
are corrosive and can burn skin.
• Like acids, bases react with indicators to produce
changes in color. Red litmus paper turns blue in bases.
Bases

8. • Some drain cleaners contain
sodium hydroxide (NaOH),
which dissolves grease, and
small pieces of aluminum.
The aluminum reacts with
the NaOH, producing
hydrogen and dislodging
solids, such as hair.
Bases

9. Name, Formula Use Other Information
Alumuminum hydroxide
(Al(OH)3)
color-fast fabrics, antacid,
water purification
sticky gel that collects
suspended clay and dirt
particles on its surface
Calcium hydroxide (Ca(OH)2) to make leather, mortar
and plaster; to lessen soil
acidity
slaked lime
Mangesium hydroxide
(Mg(OH)2)
laxative, antacid called milk of magnesia when it
is mixed with water
Ammonia (NH3) cleaners, fertilizer; to
make rayon and nylon
irritating odor that is damaging
to nasal passages and lungs
Some Common Bases and Their Uses
Bases

10. • An acid ionizes in water, producing hydronium ions
when the hydrogen ions from the acid become
attracted to water molecules.
• For example, when hydrogen chloride is added to water,
a hydronium ion and a chloride ion are produced.
Solutions of Acids and Bases

11. • Most bases are ionic compounds, made up of positive
metal ions and hydroxide ions. In water, such bases
dissociate, forming positive metal ions and hydroxide
ions.
• For example, when sodium hydroxide dissolves in water,
a sodium ion and a hydroxide ion are produced.
Solutions of Acids and Bases

12. • Some bases accept H+ ions from acids. These types of
bases ionize to produce hydroxide ions in solution, even
though they do not have the letters OH in their
formulas.
• For example, ammonia, NH3, reacts with water to
produce hydroxide ions in solution. In this case, water
acts as an acid.
Solutions of Acids and Bases

13. a source of H+ ions
D
turns blue litmus red
C
feels slippery
B
tastes sour
A
Which is NOT characteristic of an acid?
1.
CORRECT
Quiz

14. hydrogen ion
D
trihydrogen oxide ion
C
hydronium ion
B
hydroxide ion
A
Which is the term for H3O+?
2.
CORRECT
Quiz

15. Quiz
bitter-tasting
D
turn blue litmus red
C
corrosive and damaging to skin
B
produce OH– in water
A
Which is NOT characteristic of bases?
3.
CORRECT

16. H3PO4
D
NH3
C
HNO3
B
HCl
A
Which is an example of a base?
4.
CORRECT
Quiz

17. Quiz
crystallize
D
react
C
ionize
B
dissociate
A
Unlike acids, bases made up of positive metal ions and
hydroxide ions _______ in water.
5.
CORRECT