Presentation on theme: " Acids are compounds whose characteristic properties include the kinds of reactions they undergo. Properties: a. tastes sour b. reacts with metals."— Presentation transcript:
Acids are compounds whose characteristic properties include the kinds of reactions they undergo. Properties: a. tastes sour b. reacts with metals and carbonates c. turns blue litmus paper red. Common acids are hydrochloric acid, nitric acid, sulfuric acid, carbonic acid, and acetic acid.
Example: tasting a lemon. Citrus foods like grapefruits and oranges are acidic. Although sour taste is a characteristic of acids, scientists never taste chemicals in order to identify them.
Acids react with certain metals (magnesium, zinc, iron) to produce hydrogen gas. This reaction is why acids are described as corrosive. Corrosive: The way in which acids react with some metals so as to eat away the metal. Acids are used in a process called etching, Hydrochloric acid eats away metal to form designs.
One product of an acid’s reaction with carbonates is the gas carbon dioxide. Geologists use this property to identify rocks containing limestone.
Indicator: a compound that changes color when in contact with an acid or a base. Vinegar, lemon juice, and other acids turn blue litmus paper red.
Base-Another group of compounds that can be identified by their common properties a. Tastes bitter b. Feels slippery c. Turns red litmus paper blue Opposite of acids Common Bases are sodium hydroxide, calcium hydroxide, and ammonia.
Although bases are bitter, you wouldn’t want to identify them by doing a taste test. An example of a base is soap.
A slippery feeling is another characteristic of bases. Just as you avoid tasting a substance to identify it, you wouldn’t want to touch it. Strong bases can irritate or burn your skin.
Litmus paper is a safe, reliable test for acids and bases. Bases turn red litmus paper blue. An easy way to remember which color litmus turns for acids or bases is to remember the letter b. Bases turn litmus paper blue.
Unlike acids, bases don’t react with carbonates to produce carbon dioxide. Another important property of bases is how they react with acids.
Manufacturers, farmers, and builders are only some of the people who depend on acids and bases in their work. Acids are used: a. in food b. to clean brick and metals c. to treat iron and steel d. to make fertilizers Bases are used: a. To make household cleaning products b. to produce carbon dioxide in baked goods c. to make mortar and cement.