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.
BASES
B. 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.
FEEL
D. 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 & SALTS
C. 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.
PROTONS
D. 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 SCALE
F. 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.
ELECTROLYTES
G. 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.