Transcript Acids, Bases, and Salts Section 1 Acids and Bases

Chapter 23
Acids, Bases,
and
Salts
Have you seen these?
Section 1: Acids & Bases
Acid - (H+) removed in H2O.
Properties of Acids
1.
2.
3.
Taste sour
Corrosive and can burn skin
React with litmus paper: red to yellow.
Common Acids
Foods contains acids
a. Citrus fruits citric acid
b. Vinegar, or acetic acid, is in pickled foods
2. You have hydrochloric acid (HCl) in your
stomach.
1.
Common Acids
3.
Four acids vital to industry.
a.
b.
c.
d.
Sulfuric acid - used in car batteries and the
manufacturing of fertilizers
Phosphoric acid - used to manufacture detergents,
fertilizers, and soft drinks
Nitric acid - used to manufacture fertilizers and
explosive
Hydrochloric acid – used to clean steel
Bases
Base - forms hydroxide ions (OH-) in water.
Compliments or opposites of acids
Properties of Bases
1.
2.
3.
4.
Many are crystals
Feel slippery
Strong bases are corrosive
litmus paper turns blue-purple
Common Bases
1.
2.
3.
Ammonia & Sodium Hydroxide - are used
in cleaners, fertilizers, rayon, nylon
Magnesium Hydroxide - medications
Aluminum Hydroxide – color fast fabrics
Solutions of Acids and Bases
1.
2.
3.
Acid describes compounds that can be
ionized in water to form hydronium ions
Base describes compounds that can
form hydroxide ions in solution
Solutions of acids and solutions of bases
are electric conductors to some extent
Discussion Questions
1.
Why should a person never use taste
testing to identify an acid or a base?
Answers


Acids and Bases can be corrosive and
cause damage to tissue
Sulfuric, phosphoric, nitric, hydrochloric
Section 2
Strength of Acids
and Bases
The strength of an acid or a base
depends on how completely a
compound separates into ions
when dissolving in water
Strong Acids and Strong
Bases
1.
2.
3.
1.
A strong acid ionizes (or loses H+) almost
completely in solution
A strong base dissociates (or forms OH-)
completely in solution
Equations for strong acids and bases use a
single arrow indicating ions are formed
Strong acids and bases conduct more
electricity than weak ones
Weak Acids and Weak Bases
1.
2.
4.
A weak acid/base only partly ionizes in solution
Equations for weak acids and bases use
double arrows pointing in opposite directions,
indicating an incomplete reaction
Dilute and concentrated are terms to describe
the amount of acid or base dissolved
pH of a Solution
1.
pH - a measure of the concentration of
hydrogen ions (H+) in a solution or how acidic
or basic it is
a.
b.
c.
pH lower than 7 = acidic
pH greater than 7 = basic
pH exactly equal to 7 = neutral
pH of a Solution
1.
2.
pH is determined by a universal indicator
paper or pH meter
Buffers – solutions containing
ions that react with
additional acids or
bases to minimize
their effects on pH.
Discussion Question

Is a strong acid the same thing as a
concentrated acid? Why or Why Not?
Answer

Not necessarily the same; strength refers
to ionization in a solution while
concentration refers to the amount of acid
or base dissolved
Section 3
Salts
Neutralization
Chemical reaction between an acid and a
base taking place in a water solution
Hydronium ions from the acid combine with
hydroxide ions from the base to produce
neutral water
Salts
1.
2.
3.
Salt - compound formed when the
negative ions from an acid combine
with the positive ions of a base
Salt is essential for many animals
Other salt uses include manufacturing
of paint, rubber, glass, soap,
detergents, and dry cell batteries
Titration
Used to determine the concentrations of
an acidic or basic solution
2. A solution of known concentration is the
standard solution
3. An acid/base indicator is added to an
unknown solution
4. A color change that is constant
is the end point.
1.
Soaps and Detergents
Soaps
1.
Are organic salts with polar and nonpolar ends.
2.
The nonpolar, hydrocarbon end interacts with
oil and dirt
3.
The polar end helps oil and dirt dissolve in
water
Detergents
1.
Form more soluble salts with the ions in hard
water
Esters
1.
2.
3.
Come from alcohols that are not bases
but have a hydroxyl (-OH) group
Esters are used in fruit flavorings and
perfumes
Polyesters are synthetic fibers used to
make fabrics
Discussion Question

What are two ways salts can form?
Answer
1.
2.
When an acid and a base combine their
negative and positive ions
When an acid reacts with a metal