Acids and Bases
Thomas Briggs & Cierra Boone
Acids can be either strong or weak. A strong acid is considered to be between 0 and 3. This includes lemon juice and other substances such as hydrochloric acid and lime juice. Weak acids range from a PH between 4 and 6 which may include acid rain, human saliva and normal rain in some cases.
Some physical properties of acids consist of a sour taste in food, or in some acids it can destroy fabric in clothes. And some acids are so strong they actually cause burning to the skin. Some chemical properties may include color changes to whatever the substance has come in contact with. You can dissolve a pure sample of the compound in a glass of water and if the concentration of hydrogen ions goes up then it is acidic. Another way to tell is by using phenol red strips; when you put the substance of the paper and it turns a reddish pink color it is an acid.
There are two types of bases, a strong and a weak. A strong base has a PH of about 12 to 14. Strong bases consist of sodium hydroxide, potassium hydroxide and lithium hydroxide. Weak bases can range between 8 to 11. Examples of some weak bases are sea water, baking soda or even steam water.
The physical properties of bases include a slippery feeling and turn red litmus paper blue. Some chemical properties are a bitter taste.
A acid-base indicator is a weak acid or weak base. Examples of these indicators are beets, blackberries, carrots raspberries.
Baking soda can be used as an indicator by mixing it with a substance. If it fizzes it is an acid if it doesn't then its a base. Beets can change from red to purple in a basic solution.