Unit 9
Acids and Bases
What is an ACID?
a compound that releases hydrogen ions (___) in
water
(The Hydrogen is always in FRONT of the compound.)
Substances containing acids are described as ACIDIC.
What is a BASE?
a compound that releases hydroxide ions (_____) in water
(The hydroxide is always in the BACK of the compound.)
Exception: AMMONIA  NH3
Substances containing bases are described as
BASIC or ALKALINE.
Underline the ACIDS and circle the BASES below. If it’s neither, cross it out.
HCl
H2SO4
NaOH
NaCl
KOH
HBr
H3PO4
C6H12O6
Ca(OH)2
HF
KMnO4
HOH
Water is typically considered NEUTRAL  neither an acid nor a base
(The H+ and OH- ions cancel each other out.)
Properties of Acids
Mixed with certain substances; however, it can act as either an acid or a base!
PROPERTIES OF ACIDS
1. Acids taste
SOUR.
(Example: Lemons, grapefruit, sour patch kids).
2. Acids are IRRITANTS. They cause
irritations  ranging from a mild rash to severe
burns.
3. Acids are CORROSIVE - they “eat” away at
other materials - including metals, cloth, skin, wood.
Acids do not affect glass or plastic.
* This property allows certain metals to be “etched”.
Examples of Acids
Acids play an important role in the chemistry of living things. They also
make valuable products for homes, farms, and industries.
1.
ACIDS IN FOOD
Vitamin C = Ascorbic Acid (helps build
immunity)
*Found in citrus fruits and tomatoes.
Folic Acid (Vitamin used for healthy cell growth)
*Found in green leafy vegetables.
Vinegar = Acetic Acid, ethanoic acid
Soda = carbonic acid, phosphoric acid
* Acids are also found in
coffee, tea, and alcohol.
2. Acids in the Body
a. Acid in the S______________
is called HYDROCHLORIC ACID
(helps digest food)
b. LACTIC ACID builds up in the muscles during
exercise and causes soreness.
3. Acids in the Home/ Industry
a. Battery Acid = Sulfuric Acid
b. Toilet cleaners = hydrochloric acid
c. Cetain acids are even used in certain
make-up products, and topical acne & skin
treatments  Salicylic acid, Glycolic Acid
Properties of Bases
1. Bases taste
BITTER.
(Found in: tonic water, bitter chocolate, baking soda)
Certain foods taste bitter (but are not bases).
The bitter flavor is an acquired taste  beer, coffee
2. Bases have a SLIPPERY feel.
(Most bases are used to make soap or cleaning agents!)
3. Bases DO NOT react with metals (like acids),
but they are CORROSIVE to many other
substances. Bases can severely irritate/ burn/ damage skin!
Uses of Bases
1. Bases in Food
While there are many foods that are acidic, few foods are basic because
the flavor is less pleasurable.  Eggs, tonic water
* Baking Soda reacts with acids to produce CO2 gas in
baked goods. The bubbles formed help make breads,
cakes, cookies light and fluffy!
2. Bases in the Body
Blood is slightly “basic”. (pH scale = 7.4) (neutral = pH = 7)
b. Human saliva is slightly basic.
c. The mucus lining of our stomach is basic. It
a.
protects the stomach muscle from the hydrochloric
acid made there. Without this basic lining, the
stomach muscle could develop an
3.
ULCER.
Bases in the Home/ Industry
Most examples of bases are used in cleaning agents:
a. Ammonia = _____, drain cleaners & oven
cleaners (lye  sodium hydroxide), soaps,
toothpaste, bleach, shampoos, and
detergents
b. ANTACIDS  weak bases that help settle
upset stomach due to stomach acids
Example: Milk of Magnesia = Magnesium Hydroxide
TUMS & Rolaids