chapter 8 acids & bases. identifying acids a. identifying acids a. an acid is a compound that...
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CHAPTER 8ACIDS & BASES
IDENTIFYING ACIDS A. IDENTIFYING ACIDS
A. AN ACID IS A COMPOUND THAT PRODUCES
HYDRONIUM IONS (H3O+) WHEN DISSOLVED IN WATER.
B. SOME GENERAL PROPERTIES OF ACIDS INCLUDE
SOUR TASTE, REACTIVITY WITH METALS, AND ABILITY
TO PRODUCE COLOR CHANGES IN INDICATORS.
SOUR TASTE
C. SOUR TASTE
1. MANY OF THE FOODS THAT YOU EAT THAT
TASTE SOUR CONTAIN ACIDS. ALTHOUGH YOU
ACIDS ARE IN THE FOODS WE EAT, YOU
SHOULD NEVER TEST AN ACID BY TASTING IT.
REACTIVITY D. REACTIVITY WITH METALS
1. THE REACTION BETWEEN AN ACID AND A METAL IS AN EXAMPLE
OF A SINGLE REPLACEMENT REACTION.
2. WHEN YOU COVER FOODS THAT CONTAIN TOMATOES WITH
ALUMINUM FOIL, THE FOIL MAY TURN DARK, DEVELOP SMALL
HOLES, AND THE FOOD MAY HAVE A METALLIC TASTE. TOMATOES
CONTAIN CITRIC ACID, WHICH REACTS WITH METALS SUCH AS
ALUMINUM.
COLOR CHANGE
E. COLOR CHANGES IN INDICATORS
1. AN INDICATOR IS A SUBSTANCE THAT CHANGES COLOR
IN THE PRESENCE OF AN ACID OR BASE.
2. A COMMONLY USED INDICATOR IS LITMUS PAPER.
3. BLUE LITMUS PAPER TURNS RED IN THE
PRESENCE OF AN ACID.
BASESB. IDENTIFYING BASES
A. A BASE IS A COMPOUND THAT PRODUCES HYDROXIDE IONS
(OH-) WHEN DISSOLVED IN WATER.
B. SOME GENERAL PROPERTIES OF BASES INCLUDE BITTER
TASTE, SLIPPERY FEEL, AND ABILITY TO PRODUCE COLOR
CHANGES IN INDICATORS. BASES USUALLY DO NOT REACT
WITH METALS.
TASTE
C. BITTER TASTE
1. MANY OF THE FOODS THAT YOU EAT THAT TASTE
BITTER ARE BASES.
2. EXAMPLES OF THESE WOULD BE UNSWEETENED
CHOCOLATE AND LIQUID MEDICATIONS. MANY
TIMES FRUIT FLAVORINGS ARE ADDED TO MASK THE
TASTE OF BASIC SOLUTIONS.
FEELD. SLIPPERY FEEL
1. MANY ITEMS THAT YOU TOUCH ON A DAILY BASES FEEL SLIPPERY.
THIS SLIPPERY FEEL IS DUE TO THE PRODUCT CONTAINING BASES.
2. EXAMPLES OF THESE WOULD BE SOAP AND MANY CLEANING
PRODUCTS. ALSO, ROCKS THAT FEEL SLIPPERY ARE DUE TO WATER
DISSOLVING COMPOUNDS TRAPPED IN THE ROCKS WHICH PRODUCE
A BASIC SOLUTION.
COLOR
E. COLOR CHANGE IN INDICATORS
1. BASES TURN RED LITMUS PAPER BLUE. THE
LITMUS PAPER WILL CHANGE BACK TO RED IF
YOU DROP AN ACIDIC SOLUTION ON IT.
NEUTRALIZATION & SALTSC. NEUTRALIZATION AND SALTS
A. NEUTRALIZATION IS A REACTION BETWEEN AN
ACID AND A BASE.
B. DURING A NEUTRALIZATION REACTION BETWEEN
AN ACID AND A BASE WATER AND SALT ARE
PRODUCED.
PROTONSD. PROTON DONORS AND ACCEPTORS
A. ACIDS CAN BE DEFINED AS PROTON DONORS, AND BASES CAN BE
DEFINED AS PROTON ACCEPTORS.
1. ACIDS LOSE PROTONS.
2. BASES ACCEPT PROTONS.
3. WATER IS NEUTRAL. IN A REACTION WATER CAN ACT LIKE
AN ACID OR A BASE. IN SOME CASES WATER WILL ACCEPT
A PROTON AND BE A BASE, AND IN SOME CASES WATER
WILL LOSE A PROTON AND BE AN ACID.
STRENGTHS
E. STRENGTH OF ACIDS AND BASES
A. ONE WAY TO DESCRIBE THE STRENGTH OF AN ACID OR
BASE IS TO DETERMINE THE CONCENTRATION OF HYDRONIUM OR
HYDROXIDE IONS PRESENT IN A SOLUTION. ANOTHER WAY IS
TO DESCRIBE HOW READILY THOSE HYDRONIUM IONS OR
HYDROXIDE ION FORMED.
PH SCALEF. THE PH SCALE
A. CHEMISTS USE A NUMBER SCALE FROM 0 TO 14 TO
DESCRIBE THE CONCENTRATION OF HYDRONIUM IONS IN A
SOLUTION.
B. A PH OF 7 INDICATES A NEUTRAL SOLUTION.
C. A PH LESS THAN 7 INDICATES AN ACID.
D. A PH GREATER THAN 7 INDICATES A BASE.
ELECTROLYTESG. ELECTROLYTES
A. AN ELECTROLYTE IS A SUBSTANCE THAT IONIZES OR
DISSOCIATES INTO IONS WHEN IT DISSOLVES IN WATER.
B. THE RESULTING SOLUTION CAN CONDUCT ELECTRIC
CURRENT.
C. STRONG ACIDS OR BASES ARE STRONG ELECTROLYTES
BECAUSE THEY DISSOCIATE OR IONIZE ALMOST COMPLETELY
IN WATER.