SECTION #1 ACIDS
An ACID is a substance that produces Hydrogen
ions when reacting with water. The Hydrogen ion can be written as H+
. In general, acids taste sour, conduct electricity, and will give off
Hydrogen gas when reacting with a metal. Acids can be weak or
strong. A strong acid is called a Concentrated Acid.
Some examples are Sulfuric acid, Hydrochloric acid, and Nitric acid. A
weak acid is called a Dilute acid. Some examples are acetic
acid, citric acid, and carbonic acid. Acids can also turn certain
compounds a different color. These compounds are called Indicators.
One indicator is called Litmus Paper. Blue litmus paper
turns red in an acid. Red litmus paper stays red in an acid. You
must use both papers to have one complete test. Another indicator is Bromothymol
Blue Solution, (Bro. Blue). Acids turn bromothymol blue yellow.
SECTION #2 BASES
A Base is a substance that produces Hydroxide Ions when reacting with water. The Hydroxide ion can be written as OH-. In general, bases taste bitter and feel slippery. Bases can also be concentrated or dilute. Some examples are, strong base - sodium hydroxide, weak base - calcium hydroxide.
***Both acids and bases can be Corrosive. This means that they will destroy body tissue and clothing.
Bases also turn indicators color. Red litmus paper turns
blue in a base. Blue litmus paper stays blue in a base. Bromothymol
blue solution will be blue in a base.
SECTION #3 SALTS
A Salt is neither an acid or a base, it is a Neutral substance. The process by which these compounds are formed is called the Neutralization Reaction.
ACID + BASE ---------> SALT + WATER
HCl + NaOH ----------> NaCl + HOH
Neutral substances also turn indicators color. Red and
blue litmus paper will stay the same colors. Bromothymol Blue will turn
green in neutral solution.
SECTION #4 pH & THE pH SCALE
The term pH means the percent of hydrogen. The pH Scale was developed to identify, and measure the strength of, an acid or base. The pH scale goes from 1-14 with 7 as being neutral. Any number less than 7 is an acid. The lower the number the stronger the acid. The strongest acid is #1. Any number greater than 7 is a base. The higher the number the stronger the base. The strongest base is #14.
1--2--3--4--5--6--7--8--9--10--11--12--13--14
<--------ACIDS N BASES------------------->
The pH scale is used with an indicator called pHydrion Paper. When testing with this paper use the following steps.
1. Dip the test strip into the solution. Only put it in half way, don't let your fingers touch the solution.
2. Remove and immediately compare the color the test strip has turned to the color chart that was provided with the test strips.
3. Find the closest matching color and record the corresponding pH number.
4. Look up the number on the pH scale to determine if it is an acid or a base, and how strong it is.